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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Hambsch%2C+F&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Hambsch%2C+F&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Hambsch%2C+F&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Hambsch%2C+F&start=100" class="pagination-link " aria-label="Page 3" aria-current="page">3 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.16424">arXiv:2501.16424</a> <span> [<a href="https://arxiv.org/pdf/2501.16424">pdf</a>, <a href="https://arxiv.org/format/2501.16424">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Follow-up on three poorly studied AM CVn stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aungwerojwit%2C+A">Amornrat Aungwerojwit</a>, <a href="/search/astro-ph?searchtype=author&query=Gaensicke%2C+B+T">Boris T. Gaensicke</a>, <a href="/search/astro-ph?searchtype=author&query=Breedt%2C+E">E. Breedt</a>, <a href="/search/astro-ph?searchtype=author&query=Arjyotha%2C+S">S. Arjyotha</a>, <a href="/search/astro-ph?searchtype=author&query=Hermes%2C+J+J">J. J. Hermes</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Kumar%2C+A">A. Kumar</a>, <a href="/search/astro-ph?searchtype=author&query=Ramirez%2C+S+H">S. H. Ramirez</a>, <a href="/search/astro-ph?searchtype=author&query=Wilson%2C+T+G">T. G. Wilson</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V+S">V. S. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=Marsh%2C+T+R">T. R. Marsh</a>, <a href="/search/astro-ph?searchtype=author&query=Poshyachinda%2C+S">S. Poshyachinda</a>, <a href="/search/astro-ph?searchtype=author&query=Scaringi%2C+S">S. Scaringi</a>, <a href="/search/astro-ph?searchtype=author&query=Haislip%2C+J+B">J. B. Haislip</a>, <a href="/search/astro-ph?searchtype=author&query=Reichart%2C+D+E">D. E. Reichart</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2501.16424v1-abstract-short" style="display: inline;"> We report follow-up observations of three poorly studied AM CVn-type binaries: CRTS CSS150211 J091017-200813, NSV1440, and SDSSJ183131.63+420220.2. Analysing time-series photometry obtained with a range of ground-based facilities as well as with TESS, we determine the superhump period of CRTSJ0910-2008 as P_sh=29.700+-0.004min and the orbital period of NSV1440 as Porb=36.56+-0.03min. We also confi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.16424v1-abstract-full').style.display = 'inline'; document.getElementById('2501.16424v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.16424v1-abstract-full" style="display: none;"> We report follow-up observations of three poorly studied AM CVn-type binaries: CRTS CSS150211 J091017-200813, NSV1440, and SDSSJ183131.63+420220.2. Analysing time-series photometry obtained with a range of ground-based facilities as well as with TESS, we determine the superhump period of CRTSJ0910-2008 as P_sh=29.700+-0.004min and the orbital period of NSV1440 as Porb=36.56+-0.03min. We also confirm a photometric period of P=23.026+-0.097min in SDSSJ1831+4202, which is most likely the superhump period. We also report the first optical spectroscopy of CRTSJ0910-2008 and NSV1440 which unambiguously confirms both as AM CVn systems. We briefly discuss the distribution in the Hertzsprung-Russell diagram of the currently known sample of 63 AM CVn stars with known periods and Gaia data. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.16424v1-abstract-full').style.display = 'none'; document.getElementById('2501.16424v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2501.11524">arXiv:2501.11524</a> <span> [<a href="https://arxiv.org/pdf/2501.11524">pdf</a>, <a href="https://arxiv.org/format/2501.11524">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> GOTO065054+593624: a peculiar dwarf nova identified in real time via Kilonova Seekers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Killestein%2C+T+L">T. L. Killestein</a>, <a href="/search/astro-ph?searchtype=author&query=Ramsay%2C+G">G. Ramsay</a>, <a href="/search/astro-ph?searchtype=author&query=Kennedy%2C+M">M. Kennedy</a>, <a href="/search/astro-ph?searchtype=author&query=Kelsey%2C+L">L. Kelsey</a>, <a href="/search/astro-ph?searchtype=author&query=Steeghs%2C+D">D. Steeghs</a>, <a href="/search/astro-ph?searchtype=author&query=Littlefair%2C+S">S. Littlefair</a>, <a href="/search/astro-ph?searchtype=author&query=Godson%2C+B">B. Godson</a>, <a href="/search/astro-ph?searchtype=author&query=Lyman%2C+J">J. Lyman</a>, <a href="/search/astro-ph?searchtype=author&query=Pursiainen%2C+M">M. Pursiainen</a>, <a href="/search/astro-ph?searchtype=author&query=Warwick%2C+B">B. Warwick</a>, <a href="/search/astro-ph?searchtype=author&query=Krawczyk%2C+C">C. Krawczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Nuttall%2C+L+K">L. K. Nuttall</a>, <a href="/search/astro-ph?searchtype=author&query=Wickens%2C+E">E. Wickens</a>, <a href="/search/astro-ph?searchtype=author&query=Alexandrov%2C+S+D">S. D. Alexandrov</a>, <a href="/search/astro-ph?searchtype=author&query=da+Silva%2C+C+M">C. M. da Silva</a>, <a href="/search/astro-ph?searchtype=author&query=Leadbeater%2C+R">R. Leadbeater</a>, <a href="/search/astro-ph?searchtype=author&query=Ackley%2C+K">K. Ackley</a>, <a href="/search/astro-ph?searchtype=author&query=Dyer%2C+M+J">M. J. Dyer</a>, <a href="/search/astro-ph?searchtype=author&query=Jim%C3%A9nez-Ibarra%2C+F">F. Jim茅nez-Ibarra</a>, <a href="/search/astro-ph?searchtype=author&query=Ulaczyk%2C+K">K. Ulaczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Galloway%2C+D+K">D. K. Galloway</a>, <a href="/search/astro-ph?searchtype=author&query=Dhillon%2C+V+S">V. S. Dhillon</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Brien%2C+P">P. O'Brien</a>, <a href="/search/astro-ph?searchtype=author&query=Noysena%2C+K">K. Noysena</a>, <a href="/search/astro-ph?searchtype=author&query=Kotak%2C+R">R. Kotak</a> , et al. (40 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2501.11524v1-abstract-short" style="display: inline;"> Dwarf novae are a crucial astrophysical laboratory for probing the nature of accretion, binary mass transfer, and binary evolution -- yet their diverse observational characteristics continue to challenge our theoretical understanding. We here present the discovery of, and subsequent observing campaign on GOTO065054+593624 (hereafter GOTO0650), a dwarf nova of the WZ Sge type, discovered in real-ti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.11524v1-abstract-full').style.display = 'inline'; document.getElementById('2501.11524v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2501.11524v1-abstract-full" style="display: none;"> Dwarf novae are a crucial astrophysical laboratory for probing the nature of accretion, binary mass transfer, and binary evolution -- yet their diverse observational characteristics continue to challenge our theoretical understanding. We here present the discovery of, and subsequent observing campaign on GOTO065054+593624 (hereafter GOTO0650), a dwarf nova of the WZ Sge type, discovered in real-time by citizen scientists via the Kilonova Seekers citizen science project. An extensive dataset charts the photometric and spectroscopic evolution of this object, covering the first two months of its 2024 superoutburst. GOTO0650 shows a complete absence of visible emission lines during the high state, strong H and barely-detected He~II emission, and high-amplitude echo outbursts with a rapidly decreasing timescale that together do not neatly fit in with our current view of cataclysmic variables. The comprehensive dataset presented here not only underscores the uniqueness of this dwarf nova and marks it as a candidate period bouncer, but also highlights the important contribution that citizen scientists can make to the study of Galactic transients. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2501.11524v1-abstract-full').style.display = 'none'; document.getElementById('2501.11524v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 January, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 14 figures. Submitted to A&A</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.03616">arXiv:2410.03616</a> <span> [<a href="https://arxiv.org/pdf/2410.03616">pdf</a>, <a href="https://arxiv.org/format/2410.03616">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> A long-duration superflare on the K giant HD 251108 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=G%C3%BCnther%2C+H+M">Hans Moritz G眉nther</a>, <a href="/search/astro-ph?searchtype=author&query=Pasham%2C+D">Dheeraj Pasham</a>, <a href="/search/astro-ph?searchtype=author&query=Binks%2C+A">Alexander Binks</a>, <a href="/search/astro-ph?searchtype=author&query=Czesla%2C+S">Stefan Czesla</a>, <a href="/search/astro-ph?searchtype=author&query=Enoto%2C+T">Teruaki Enoto</a>, <a href="/search/astro-ph?searchtype=author&query=Fausnaugh%2C+M">Michael Fausnaugh</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Inoue%2C+S">Shun Inoue</a>, <a href="/search/astro-ph?searchtype=author&query=Maehara%2C+H">Hiroyuki Maehara</a>, <a href="/search/astro-ph?searchtype=author&query=Notsu%2C+Y">Yuta Notsu</a>, <a href="/search/astro-ph?searchtype=author&query=Robrade%2C+J">Jan Robrade</a>, <a href="/search/astro-ph?searchtype=author&query=Schmitt%2C+J+H+M+M">J. H. M. M. Schmitt</a>, <a href="/search/astro-ph?searchtype=author&query=Schneider%2C+P+C">P. C. Schneider</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.03616v1-abstract-short" style="display: inline;"> Many giant stars are magnetically active, which causes rotational variability, chromospheric emission lines, and X-ray emission. Large outbursts in these emission features can set limits on the magnetic field strength and thus constrain the mechanism of the underlying dynamo. HD~251108 is a Li-rich active K-type giant. We find a rotational period of 21.3~d with color changes and additional long-te… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.03616v1-abstract-full').style.display = 'inline'; document.getElementById('2410.03616v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.03616v1-abstract-full" style="display: none;"> Many giant stars are magnetically active, which causes rotational variability, chromospheric emission lines, and X-ray emission. Large outbursts in these emission features can set limits on the magnetic field strength and thus constrain the mechanism of the underlying dynamo. HD~251108 is a Li-rich active K-type giant. We find a rotational period of 21.3~d with color changes and additional long-term photometric variability. Both can be explained with very stable stellar spots. We followed the decay phase of a superflare for 28 days with NICER and from the ground. We track the flare decay in unprecedented detail in several coronal temperature components. With a peak flux around $10^{34}$~erg~s$^{-1}$ (0.5-4.0~keV) and an exponential decay time of 2.2~days in the early decay phase, this is one of the strongest flares ever observed; yet it follows trends established from samples of smaller flares, for example for the relations between H$伪$ and X-ray flux, indicating that the physical process that powers the flare emission is consistent over a large range of flare energies. We estimate a flare loop length about 2-4 times the stellar radius. No evidence is seen for abundance changes during the flare. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.03616v1-abstract-full').style.display = 'none'; document.getElementById('2410.03616v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">submitted to ApJ, one electronic figures and data will be available with the journal publication. The version on arXiv contains a static image of that figure</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.13783">arXiv:2408.13783</a> <span> [<a href="https://arxiv.org/pdf/2408.13783">pdf</a>, <a href="https://arxiv.org/ps/2408.13783">ps</a>, <a href="https://arxiv.org/format/2408.13783">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> MASTER OT J030227.28+191754.5: an unprecedentedly energetic dwarf nova outburst </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Tampo%2C+Y">Yusuke Tampo</a>, <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Isogai%2C+K">Keisuke Isogai</a>, <a href="/search/astro-ph?searchtype=author&query=Kimura%2C+M">Mariko Kimura</a>, <a href="/search/astro-ph?searchtype=author&query=Kojiguchi%2C+N">Naoto Kojiguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Nogami%2C+D">Daisaku Nogami</a>, <a href="/search/astro-ph?searchtype=author&query=Ito%2C+J">Junpei Ito</a>, <a href="/search/astro-ph?searchtype=author&query=Shibata%2C+M">Masaaki Shibata</a>, <a href="/search/astro-ph?searchtype=author&query=Yamanaka%2C+M">Masayuki Yamanaka</a>, <a href="/search/astro-ph?searchtype=author&query=Taguchi%2C+K">Kenta Taguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Maehara%2C+H">Hiroyuki Maehara</a>, <a href="/search/astro-ph?searchtype=author&query=Itoh%2C+H">Hiroshi Itoh</a>, <a href="/search/astro-ph?searchtype=author&query=Matsumoto%2C+K">Katsura Matsumoto</a>, <a href="/search/astro-ph?searchtype=author&query=Nakagawa%2C+M">Momoka Nakagawa</a>, <a href="/search/astro-ph?searchtype=author&query=Nishida%2C+Y">Yukitaka Nishida</a>, <a href="/search/astro-ph?searchtype=author&query=Dvorak%2C+S">Shawn Dvorak</a>, <a href="/search/astro-ph?searchtype=author&query=Murata%2C+K+L">Katsuhiro L. Murata</a>, <a href="/search/astro-ph?searchtype=author&query=Hosokawa%2C+R">Ryohei Hosokawa</a>, <a href="/search/astro-ph?searchtype=author&query=Imai%2C+Y">Yuri Imai</a>, <a href="/search/astro-ph?searchtype=author&query=Ito%2C+N">Naohiro Ito</a>, <a href="/search/astro-ph?searchtype=author&query=Niwano%2C+M">Masafumi Niwano</a>, <a href="/search/astro-ph?searchtype=author&query=Sato%2C+S">Shota Sato</a>, <a href="/search/astro-ph?searchtype=author&query=Noto%2C+R">Ryotaro Noto</a>, <a href="/search/astro-ph?searchtype=author&query=Yamaguchi%2C+R">Ryodai Yamaguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Schramm%2C+M">Malte Schramm</a> , et al. (38 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.13783v1-abstract-short" style="display: inline;"> We present a detailed study of the MASTER OT J030227.28+191754.5 outburst in 2021-2022, reaching an amplitude of 10.2 mag and a duration of 60 d. The detections of (1) the double-peaked optical emission lines, and (2) the early and ordinary superhumps, established that MASTER OT J030227.28+191754.5 is an extremely energetic WZ Sge-type dwarf nova (DN). Based on the superhump observations, we obtai… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.13783v1-abstract-full').style.display = 'inline'; document.getElementById('2408.13783v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.13783v1-abstract-full" style="display: none;"> We present a detailed study of the MASTER OT J030227.28+191754.5 outburst in 2021-2022, reaching an amplitude of 10.2 mag and a duration of 60 d. The detections of (1) the double-peaked optical emission lines, and (2) the early and ordinary superhumps, established that MASTER OT J030227.28+191754.5 is an extremely energetic WZ Sge-type dwarf nova (DN). Based on the superhump observations, we obtained its orbital period and mass ratio as 0.05986(1) d and 0.063(1), respectively. These are within a typical range of low-mass-ratio DNe. According to the binary parameters derived based on the thermal-tidal instability model, our analyses showed that (1) the standard disk model requires an accretion rate $\simeq$ 10$^{20}$ g s$^{-1}$ to explain its peak optical luminosity and (2) large mass was stored in the disk at the outburst onset. These cannot be explained solely by the impact of its massive ($\gtrsim$ 1.15 M$_\odot$) primary white dwarf implied by Kimura et al. (2023). Instead, we propose that the probable origin of this enormously energetic DN outburst is the even lower quiescence viscosity than other WZ Sge-type DNe. This discussion is qualitatively valid for most possible binary parameter spaces unless the inclination is low ($\lesssim 40^\circ$) enough for the disk to be bright explaining the outburst amplitude. Such low inclinations, however, would not allow detectable amplitude of early superhumps in the current thermal-tidal instability model. The optical spectra at outburst maximum showed the strong emission lines of Balmer, He I, and He II series whose core is narrower than $\sim 800$ km s$^{-1}$. Considering its binary parameters, a Keplerian disk cannot explain this narrow component, but the presumable origin is disk winds. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.13783v1-abstract-full').style.display = 'none'; document.getElementById('2408.13783v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 13 figures, 2 tables. Accepted by PASJ. Part of the online supplemental information is included</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.05420">arXiv:2404.05420</a> <span> [<a href="https://arxiv.org/pdf/2404.05420">pdf</a>, <a href="https://arxiv.org/format/2404.05420">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Accretion Funnel Reconfiguration during an Outburst in a Young Stellar Object: EX Lupi </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Singh%2C+K">Koshvendra Singh</a>, <a href="/search/astro-ph?searchtype=author&query=Ninan%2C+J+P">Joe P. Ninan</a>, <a href="/search/astro-ph?searchtype=author&query=Romanova%2C+M+M">Marina M. Romanova</a>, <a href="/search/astro-ph?searchtype=author&query=Buckley%2C+D+A+H">David A. H. Buckley</a>, <a href="/search/astro-ph?searchtype=author&query=Ojha%2C+D+K">Devendra K. Ojha</a>, <a href="/search/astro-ph?searchtype=author&query=Ghosh%2C+A">Arpan Ghosh</a>, <a href="/search/astro-ph?searchtype=author&query=Monson%2C+A">Andrew Monson</a>, <a href="/search/astro-ph?searchtype=author&query=Schramm%2C+M">Malte Schramm</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+S">Saurabh Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Reichart%2C+D+E">Daniel E. Reichart</a>, <a href="/search/astro-ph?searchtype=author&query=Mikolajewska%2C+J">Joanna Mikolajewska</a>, <a href="/search/astro-ph?searchtype=author&query=Beamin%2C+J+C">Juan Carlos Beamin</a>, <a href="/search/astro-ph?searchtype=author&query=Borissova%2C+J">J. Borissova</a>, <a href="/search/astro-ph?searchtype=author&query=Ivanov%2C+V+D">Valentin D. Ivanov</a>, <a href="/search/astro-ph?searchtype=author&query=Kouprianov%2C+V+V">Vladimir V. Kouprianov</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Pearce%2C+A">Andrew Pearce</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.05420v1-abstract-short" style="display: inline;"> EX Lupi, a low-mass young stellar object, went into an accretion-driven outburst in March of 2022. The outburst caused a sudden phase change of ~ 112$^{\circ}$ $\pm$ 5$^{\circ}$ in periodically oscillating multiband lightcurves. Our high resolution spectra obtained with HRS on SALT also revealed a consistent phase change in the periodically varying radial velocities, along with an increase in the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.05420v1-abstract-full').style.display = 'inline'; document.getElementById('2404.05420v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.05420v1-abstract-full" style="display: none;"> EX Lupi, a low-mass young stellar object, went into an accretion-driven outburst in March of 2022. The outburst caused a sudden phase change of ~ 112$^{\circ}$ $\pm$ 5$^{\circ}$ in periodically oscillating multiband lightcurves. Our high resolution spectra obtained with HRS on SALT also revealed a consistent phase change in the periodically varying radial velocities, along with an increase in the radial velocity amplitude of various emission lines. The phase change and increase of radial velocity amplitude morphologically translates to a change in the azimuthal and latitudinal location of the accretion hotspot over the stellar surface, which indicates a reconfiguration of the accretion funnel geometry. Our 3D MHD simulations reproduce the phase change for EX Lupi. To explain the observations we explored the possibility of forward shifting of the dipolar accretion funnel as well as the possibility of an emergence of a new accretion funnel. During the outburst, we also found evidence of the hotspot's morphology extending azimuthally, asymmetrically with a leading hot edge and cold tail along the stellar rotation. Our high cadence photometry showed that the accretion flow has clumps. We also detected possible clumpy accretion events in the HRS spectra, that showed episodically highly blue-shifted wings in the Ca II IRT and Balmer H lines. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.05420v1-abstract-full').style.display = 'none'; document.getElementById('2404.05420v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in The Astrophysical Journal</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.06347">arXiv:2402.06347</a> <span> [<a href="https://arxiv.org/pdf/2402.06347">pdf</a>, <a href="https://arxiv.org/ps/2402.06347">ps</a>, <a href="https://arxiv.org/format/2402.06347">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Optical and soft X-ray light-curve analysis during the 2022 eruption of U Scorpii: structural changes in the accretion disk </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Muraoka%2C+K">Katsuki Muraoka</a>, <a href="/search/astro-ph?searchtype=author&query=Kojiguchi%2C+N">Naoto Kojiguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Ito%2C+J">Junpei Ito</a>, <a href="/search/astro-ph?searchtype=author&query=Nogami%2C+D">Daisaku Nogami</a>, <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Tampo%2C+Y">Yusuke Tampo</a>, <a href="/search/astro-ph?searchtype=author&query=Taguchi%2C+K">Kenta Taguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Isogai%2C+K">Keisuke Isogai</a>, <a href="/search/astro-ph?searchtype=author&query=Arranz%2C+T">Teofilo Arranz</a>, <a href="/search/astro-ph?searchtype=author&query=Blackwell%2C+J">John Blackwell</a>, <a href="/search/astro-ph?searchtype=author&query=Blane%2C+D">David Blane</a>, <a href="/search/astro-ph?searchtype=author&query=Brincat%2C+S+M">Stephen M. Brincat</a>, <a href="/search/astro-ph?searchtype=author&query=Coates%2C+G">Graeme Coates</a>, <a href="/search/astro-ph?searchtype=author&query=Cooney%2C+W">Walter Cooney</a>, <a href="/search/astro-ph?searchtype=author&query=Dvorak%2C+S">Shawn Dvorak</a>, <a href="/search/astro-ph?searchtype=author&query=Galdies%2C+C">Charles Galdies</a>, <a href="/search/astro-ph?searchtype=author&query=Glomski%2C+D">Daniel Glomski</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Harris%2C+B">Barbara Harris</a>, <a href="/search/astro-ph?searchtype=author&query=Hodge%2C+J">John Hodge</a>, <a href="/search/astro-ph?searchtype=author&query=Hern%C3%A1ndez-Verdejo%2C+J+L">Jose L. Hern谩ndez-Verdejo</a>, <a href="/search/astro-ph?searchtype=author&query=Iozzi%2C+M">Marco Iozzi</a>, <a href="/search/astro-ph?searchtype=author&query=Itoh%2C+H">Hiroshi Itoh</a>, <a href="/search/astro-ph?searchtype=author&query=Kiyota%2C+S">Seiichiro Kiyota</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+D">Darrell Lee</a> , et al. (30 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.06347v2-abstract-short" style="display: inline;"> We present our optical photometric observations of the 2022 eruption of the recurrent nova U Scorpii (U Sco) using 49,152 data points over 70 d following the optical peak. We have also analyzed its soft X-ray (0.3--1 keV) light curve by the Neil Gehrels Swift Observatory. During the 2022 eruption, the optical plateau stage started 13.8--15.0 d and ended 23.8--25.0 d after the optical peak. The sof… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.06347v2-abstract-full').style.display = 'inline'; document.getElementById('2402.06347v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.06347v2-abstract-full" style="display: none;"> We present our optical photometric observations of the 2022 eruption of the recurrent nova U Scorpii (U Sco) using 49,152 data points over 70 d following the optical peak. We have also analyzed its soft X-ray (0.3--1 keV) light curve by the Neil Gehrels Swift Observatory. During the 2022 eruption, the optical plateau stage started 13.8--15.0 d and ended 23.8--25.0 d after the optical peak. The soft X-ray stage started 14.6--15.3 d and ended 38.7--39.5 d after the optical peak. Both stages started later and had shorter durations, and the soft X-ray light curve peaked earlier and was less luminous compared to those during the U Sco 2010 eruption. These points suggest that there were differences in the envelope mass between the different cycles of the nova eruption. Furthermore, we have analyzed the optical eclipses during the 2022 eruption. The primary eclipse was first observed 10.4--11.6 d after the optical peak, earlier than the beginning of the optical plateau stage. This sequence of events can be explained by the receding ejecta photosphere associated with the expanding nova ejecta. We have determined the ingress and egress phases of the primary eclipses and estimated the outer radius of the optical light source centered at the white dwarf (WD). During the optical plateau stage, the source radius remained $\sim$1.2 times larger than the Roche volume radius of the primary WD, being close to the L1 point. When the optical plateau stage ended, the source radius drastically shrank to the tidal truncation radius within a few orbital periods. This previously unresolved phenomenon can be interpreted as a structural change in U Sco where the temporarily expanded accretion disk due to the nova wind returned to a steady state. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.06347v2-abstract-full').style.display = 'none'; document.getElementById('2402.06347v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 7 figures, 7 tables, accepted for publication in PASJ; doi:10.1093/pasj/psae010</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">MSC Class:</span> 85-11 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.16883">arXiv:2401.16883</a> <span> [<a href="https://arxiv.org/pdf/2401.16883">pdf</a>, <a href="https://arxiv.org/format/2401.16883">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> </div> <p class="title is-5 mathjax"> A survey for variable young stars with small telescopes: VIII -- Properties of 1687 Gaia selected members in 21 nearby clusters </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Froebrich%2C+D">Dirk Froebrich</a>, <a href="/search/astro-ph?searchtype=author&query=Scholz%2C+A">Aleks Scholz</a>, <a href="/search/astro-ph?searchtype=author&query=Campbell-White%2C+J">Justyn Campbell-White</a>, <a href="/search/astro-ph?searchtype=author&query=Vanaverbeke%2C+S">Siegfried Vanaverbeke</a>, <a href="/search/astro-ph?searchtype=author&query=Herbert%2C+C">Carys Herbert</a>, <a href="/search/astro-ph?searchtype=author&query=Eisl%C3%B6ffel%2C+J">Jochen Eisl枚ffel</a>, <a href="/search/astro-ph?searchtype=author&query=Urtly%2C+T">Thomas Urtly</a>, <a href="/search/astro-ph?searchtype=author&query=Long%2C+T+P">Timothy P. Long</a>, <a href="/search/astro-ph?searchtype=author&query=Walton%2C+I+L">Ivan L. Walton</a>, <a href="/search/astro-ph?searchtype=author&query=Wiersema%2C+K">Klaas Wiersema</a>, <a href="/search/astro-ph?searchtype=author&query=Quinn%2C+N+J">Nick J. Quinn</a>, <a href="/search/astro-ph?searchtype=author&query=Rodda%2C+T">Tony Rodda</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez-Carballo%2C+J">Juan-Luis Gonz谩lez-Carballo</a>, <a href="/search/astro-ph?searchtype=author&query=Aimar%2C+M+M">Mario Morales Aimar</a>, <a href="/search/astro-ph?searchtype=author&query=Garc%C3%ADa%2C+R+C">Rafael Castillo Garc铆a</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+F+C+S">Francisco C. Sold谩n Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=de+la+Cuesta%2C+F+G">Faustino Garc铆a de la Cuesta</a>, <a href="/search/astro-ph?searchtype=author&query=Licchelli%2C+D">Domenico Licchelli</a>, <a href="/search/astro-ph?searchtype=author&query=Perez%2C+A+E">Alex Escartin Perez</a>, <a href="/search/astro-ph?searchtype=author&query=Gonz%C3%A1lez%2C+J+L+S">Jos茅 Luis Salto Gonz谩lez</a>, <a href="/search/astro-ph?searchtype=author&query=Deldem%2C+M">Marc Deldem</a>, <a href="/search/astro-ph?searchtype=author&query=Futcher%2C+S+R+L">Stephen R. L. Futcher</a>, <a href="/search/astro-ph?searchtype=author&query=Nelson%2C+T">Tim Nelson</a>, <a href="/search/astro-ph?searchtype=author&query=Dvorak%2C+S">Shawn Dvorak</a>, <a href="/search/astro-ph?searchtype=author&query=Mo%C5%BAdzierski%2C+D">Dawid Mo藕dzierski</a> , et al. (38 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.16883v1-abstract-short" style="display: inline;"> The Hunting Outbursting Young Stars (HOYS) project performs long-term, optical, multi-filter, high cadence monitoring of 25 nearby young clusters and star forming regions. Utilising Gaia DR3 data we have identified about 17000 potential young stellar members in 45 coherent astrometric groups in these fields. Twenty one of them are clear young groups or clusters of stars within one kiloparsec and t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.16883v1-abstract-full').style.display = 'inline'; document.getElementById('2401.16883v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.16883v1-abstract-full" style="display: none;"> The Hunting Outbursting Young Stars (HOYS) project performs long-term, optical, multi-filter, high cadence monitoring of 25 nearby young clusters and star forming regions. Utilising Gaia DR3 data we have identified about 17000 potential young stellar members in 45 coherent astrometric groups in these fields. Twenty one of them are clear young groups or clusters of stars within one kiloparsec and they contain 9143 Gaia selected potential members. The cluster distances, proper motions and membership numbers are determined. We analyse long term (about 7yr) V, R, and I-band light curves from HOYS for 1687 of the potential cluster members. One quarter of the stars are variable in all three optical filters, and two thirds of these have light curves that are symmetric around the mean. Light curves affected by obscuration from circumstellar materials are more common than those affected by accretion bursts, by a factor of 2-4. The variability fraction in the clusters ranges from 10 to almost 100 percent, and correlates positively with the fraction of stars with detectable inner disks, indicating that a lot of variability is driven by the disk. About one in six variables shows detectable periodicity, mostly caused by magnetic spots. Two thirds of the periodic variables with disk excess emission are slow rotators, and amongst the stars without disk excess two thirds are fast rotators - in agreement with rotation being slowed down by the presence of a disk. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.16883v1-abstract-full').style.display = 'none'; document.getElementById('2401.16883v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">accepted for publication in MNRAS, 1 table, 9 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.08360">arXiv:2310.08360</a> <span> [<a href="https://arxiv.org/pdf/2310.08360">pdf</a>, <a href="https://arxiv.org/format/2310.08360">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> A planetary collision afterglow and transit of the resultant debris cloud </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kenworthy%2C+M">Matthew Kenworthy</a>, <a href="/search/astro-ph?searchtype=author&query=Lock%2C+S">Simon Lock</a>, <a href="/search/astro-ph?searchtype=author&query=Kennedy%2C+G">Grant Kennedy</a>, <a href="/search/astro-ph?searchtype=author&query=van+Capelleveen%2C+R">Richelle van Capelleveen</a>, <a href="/search/astro-ph?searchtype=author&query=Mamajek%2C+E">Eric Mamajek</a>, <a href="/search/astro-ph?searchtype=author&query=Carone%2C+L">Ludmila Carone</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Masiero%2C+J">Joseph Masiero</a>, <a href="/search/astro-ph?searchtype=author&query=Mainzer%2C+A">Amy Mainzer</a>, <a href="/search/astro-ph?searchtype=author&query=Kirkpatrick%2C+J+D">J. Davy Kirkpatrick</a>, <a href="/search/astro-ph?searchtype=author&query=Gomez%2C+E">Edward Gomez</a>, <a href="/search/astro-ph?searchtype=author&query=Leinhardt%2C+Z">Zo毛 Leinhardt</a>, <a href="/search/astro-ph?searchtype=author&query=Dou%2C+J">Jingyao Dou</a>, <a href="/search/astro-ph?searchtype=author&query=Tanna%2C+P">Pavan Tanna</a>, <a href="/search/astro-ph?searchtype=author&query=Sainio%2C+A">Arttu Sainio</a>, <a href="/search/astro-ph?searchtype=author&query=Barker%2C+H">Hamish Barker</a>, <a href="/search/astro-ph?searchtype=author&query=Charbonnel%2C+S">St茅phane Charbonnel</a>, <a href="/search/astro-ph?searchtype=author&query=Garde%2C+O">Olivier Garde</a>, <a href="/search/astro-ph?searchtype=author&query=D%C3%BB%2C+P+L">Pascal Le D没</a>, <a href="/search/astro-ph?searchtype=author&query=Mulato%2C+L">Lionel Mulato</a>, <a href="/search/astro-ph?searchtype=author&query=Petit%2C+T">Thomas Petit</a>, <a href="/search/astro-ph?searchtype=author&query=Smith%2C+M+R">Michael Rizzo Smith</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.08360v1-abstract-short" style="display: inline;"> Planets grow in rotating disks of dust and gas around forming stars, some of which can subsequently collide in giant impacts after the gas component is removed from the disk. Monitoring programs with the warm Spitzer mission have recorded significant and rapid changes in mid-infrared output for several stars, interpreted as variations in the surface area of warm dusty material ejected by planetary… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.08360v1-abstract-full').style.display = 'inline'; document.getElementById('2310.08360v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.08360v1-abstract-full" style="display: none;"> Planets grow in rotating disks of dust and gas around forming stars, some of which can subsequently collide in giant impacts after the gas component is removed from the disk. Monitoring programs with the warm Spitzer mission have recorded significant and rapid changes in mid-infrared output for several stars, interpreted as variations in the surface area of warm dusty material ejected by planetary-scale collisions and heated by the central star: e.g., NGC 2354-ID8, HD 166191 and V844 Persei. Here we report combined observations of the young (about 300 Myr), solar-like star ASASSN-21qj: an infrared brightening consistent with a blackbody temperature of 1000 K and a luminosity of 4 percent of that of the star lasting for about 1000 days, partially overlapping in time with a complex and deep wavelength-dependent optical eclipse that lasted for about 500 days. The optical eclipse started 2.5 years after the infrared brightening, implying an orbital period of at least that duration. These observations are consistent with a collision between two exoplanets of several to tens of Earth masses at 2 to 16 au from the central star. Such an impact produces a hot, highly-extended post-impact remnant with sufficient luminosity to explain the infrared observations. Transit of the impact debris, sheared by orbital motion into a long cloud, causes the subsequent complex eclipse of the host star. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.08360v1-abstract-full').style.display = 'none'; document.getElementById('2310.08360v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">28 pages, 9 figures, 2 tables, author's Accepted Manuscript version, reproducible workflow built with showyourwork; open-source code can be found at https://github.com/mkenworthy/ASASSN-21qj-collision/</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> 2023, Nature, 622, 251-254. Published 2023 October 11 at https://www.nature.com/articles/s41586-023-06573-9 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.03944">arXiv:2309.03944</a> <span> [<a href="https://arxiv.org/pdf/2309.03944">pdf</a>, <a href="https://arxiv.org/format/2309.03944">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Gaia22dkvLb: A Microlensing Planet Potentially Accessible to Radial-Velocity Characterization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wu%2C+Z">Zexuan Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+S">Subo Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Yi%2C+T">Tuan Yi</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+Z">Zhuokai Liu</a>, <a href="/search/astro-ph?searchtype=author&query=El-Badry%2C+K">Kareem El-Badry</a>, <a href="/search/astro-ph?searchtype=author&query=Gould%2C+A">Andrew Gould</a>, <a href="/search/astro-ph?searchtype=author&query=Wyrzykowski%2C+L">L. Wyrzykowski</a>, <a href="/search/astro-ph?searchtype=author&query=Rybicki%2C+K+A">K. A. Rybicki</a>, <a href="/search/astro-ph?searchtype=author&query=Bachelet%2C+E">Etienne Bachelet</a>, <a href="/search/astro-ph?searchtype=author&query=Christie%2C+G+W">Grant W. Christie</a>, <a href="/search/astro-ph?searchtype=author&query=de+Almeida%2C+L">L. de Almeida</a>, <a href="/search/astro-ph?searchtype=author&query=Monard%2C+L+A+G">L. A. G. Monard</a>, <a href="/search/astro-ph?searchtype=author&query=McCormick%2C+J">J. McCormick</a>, <a href="/search/astro-ph?searchtype=author&query=Natusch%2C+T">Tim Natusch</a>, <a href="/search/astro-ph?searchtype=author&query=Zielinski%2C+P">P. Zielinski</a>, <a href="/search/astro-ph?searchtype=author&query=Chen%2C+H">Huiling Chen</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+Y">Yang Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+C">Chang Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Merand%2C+A">A. Merand</a>, <a href="/search/astro-ph?searchtype=author&query=Mroz%2C+P">Przemek Mroz</a>, <a href="/search/astro-ph?searchtype=author&query=Shangguan%2C+J">Jinyi Shangguan</a>, <a href="/search/astro-ph?searchtype=author&query=Udalski%2C+A">Andrzej Udalski</a>, <a href="/search/astro-ph?searchtype=author&query=Woillez%2C+J">J. Woillez</a>, <a href="/search/astro-ph?searchtype=author&query=Zhang%2C+H">Huawei Zhang</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a> , et al. (28 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.03944v2-abstract-short" style="display: inline;"> We report discovering an exoplanet from following up a microlensing event alerted by Gaia. The event Gaia22dkv is toward a disk source rather than the traditional bulge microlensing fields. Our primary analysis yields a Jovian planet with M_p = 0.59^{+0.15}_{-0.05} M_J at a projected orbital separation r_perp = 1.4^{+0.8}_{-0.3} AU, and the host is a ~1.1 M_sun turnoff star at ~1.3 kpc. At r'~14,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.03944v2-abstract-full').style.display = 'inline'; document.getElementById('2309.03944v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.03944v2-abstract-full" style="display: none;"> We report discovering an exoplanet from following up a microlensing event alerted by Gaia. The event Gaia22dkv is toward a disk source rather than the traditional bulge microlensing fields. Our primary analysis yields a Jovian planet with M_p = 0.59^{+0.15}_{-0.05} M_J at a projected orbital separation r_perp = 1.4^{+0.8}_{-0.3} AU, and the host is a ~1.1 M_sun turnoff star at ~1.3 kpc. At r'~14, the host is far brighter than any previously discovered microlensing planet host, opening up the opportunity of testing the microlensing model with radial velocity (RV) observations. RV data can be used to measure the planet's orbital period and eccentricity, and they also enable searching for inner planets of the microlensing cold Jupiter, as expected from the ''inner-outer correlation'' inferred from Kepler and RV discoveries. Furthermore, we show that Gaia astrometric microlensing will not only allow precise measurements of its angular Einstein radius theta_E, but also directly measure the microlens parallax vector and unambiguously break a geometric light-curve degeneracy, leading to definitive characterization of the lens system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.03944v2-abstract-full').style.display = 'none'; document.getElementById('2309.03944v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted by AJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.12450">arXiv:2308.12450</a> <span> [<a href="https://arxiv.org/pdf/2308.12450">pdf</a>, <a href="https://arxiv.org/format/2308.12450">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ad2c0d">10.3847/1538-4357/ad2c0d <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ground-based and JWST Observations of SN 2022pul: II. Evidence from Nebular Spectroscopy for a Violent Merger in a Peculiar Type-Ia Supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kwok%2C+L+A">Lindsey A. Kwok</a>, <a href="/search/astro-ph?searchtype=author&query=Siebert%2C+M+R">Matthew R. Siebert</a>, <a href="/search/astro-ph?searchtype=author&query=Johansson%2C+J">Joel Johansson</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Blondin%2C+S">Stephane Blondin</a>, <a href="/search/astro-ph?searchtype=author&query=Dessart%2C+L">Luc Dessart</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">Ryan J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Hillier%2C+D+J">D. John Hillier</a>, <a href="/search/astro-ph?searchtype=author&query=Larison%2C+C">Conor Larison</a>, <a href="/search/astro-ph?searchtype=author&query=Pakmor%2C+R">Ruediger Pakmor</a>, <a href="/search/astro-ph?searchtype=author&query=Temim%2C+T">Tea Temim</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">Katie Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Badenes%2C+C">Carles Badenes</a>, <a href="/search/astro-ph?searchtype=author&query=Barna%2C+B">Barnabas Barna</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Newman%2C+M+J+B">Max J. Brenner Newman</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Bustamante-Rosell%2C+M+J">Maria Jose Bustamante-Rosell</a>, <a href="/search/astro-ph?searchtype=author&query=Camacho-Neves%2C+Y">Yssavo Camacho-Neves</a>, <a href="/search/astro-ph?searchtype=author&query=Clocchiatti%2C+A">Alejandro Clocchiatti</a>, <a href="/search/astro-ph?searchtype=author&query=Coulter%2C+D+A">David A. Coulter</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+K+W">Kyle W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Deckers%2C+M">Maxime Deckers</a>, <a href="/search/astro-ph?searchtype=author&query=Dimitriadis%2C+G">Georgios Dimitriadis</a> , et al. (56 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.12450v2-abstract-short" style="display: inline;"> We present an analysis of ground-based and JWST observations of SN~2022pul, a peculiar "03fg-like" (or "super-Chandrasekhar") Type Ia supernova (SN Ia), in the nebular phase at 338d post explosion. Our combined spectrum continuously covers 0.4--14 $渭$m and includes the first mid-infrared spectrum of an 03fg-like SN Ia. Compared to normal SN Ia 2021aefx, SN 2022pul exhibits a lower mean ionization… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.12450v2-abstract-full').style.display = 'inline'; document.getElementById('2308.12450v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.12450v2-abstract-full" style="display: none;"> We present an analysis of ground-based and JWST observations of SN~2022pul, a peculiar "03fg-like" (or "super-Chandrasekhar") Type Ia supernova (SN Ia), in the nebular phase at 338d post explosion. Our combined spectrum continuously covers 0.4--14 $渭$m and includes the first mid-infrared spectrum of an 03fg-like SN Ia. Compared to normal SN Ia 2021aefx, SN 2022pul exhibits a lower mean ionization state, asymmetric emission-line profiles, stronger emission from the intermediate-mass elements (IMEs) argon and calcium, weaker emission from iron-group elements (IGEs), and the first unambiguous detection of neon in a SN Ia. Strong, broad, centrally peaked [Ne II] line at 12.81 $渭$m was previously predicted as a hallmark of "violent merger'' SN Ia models, where dynamical interaction between two sub-$M_{ch}$ white dwarfs (WDs) causes disruption of the lower mass WD and detonation of the other. The violent merger scenario was already a leading hypothesis for 03fg-like SNe Ia; in SN 2022pul it can explain the large-scale ejecta asymmetries seen between the IMEs and IGEs and the central location of narrow oxygen and broad neon. We modify extant models to add clumping of the ejecta to better reproduce the optical iron emission, and add mass in the innermost region ($< 2000$ km s$^{-1}$) to account for the observed narrow [O I]~$位\lambda6300$, 6364 emission. A violent WD-WD merger explains many of the observations of SN 2022pul, and our results favor this model interpretation for the subclass of 03fg-like SN Ia. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.12450v2-abstract-full').style.display = 'none'; document.getElementById('2308.12450v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages, 10 figures, published in ApJ</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal, Volume 966, Issue 1, id.135, 18 pp., May 2024 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.12449">arXiv:2308.12449</a> <span> [<a href="https://arxiv.org/pdf/2308.12449">pdf</a>, <a href="https://arxiv.org/format/2308.12449">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Ground-based and JWST Observations of SN 2022pul: I. Unusual Signatures of Carbon, Oxygen, and Circumstellar Interaction in a Peculiar Type Ia Supernova </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Siebert%2C+M+R">Matthew R. Siebert</a>, <a href="/search/astro-ph?searchtype=author&query=Kwok%2C+L+A">Lindsey A. Kwok</a>, <a href="/search/astro-ph?searchtype=author&query=Johansson%2C+J">Joel Johansson</a>, <a href="/search/astro-ph?searchtype=author&query=Jha%2C+S+W">Saurabh W. Jha</a>, <a href="/search/astro-ph?searchtype=author&query=Blondin%2C+S">St茅phane Blondin</a>, <a href="/search/astro-ph?searchtype=author&query=Dessart%2C+L">Luc Dessart</a>, <a href="/search/astro-ph?searchtype=author&query=Foley%2C+R+J">Ryan J. Foley</a>, <a href="/search/astro-ph?searchtype=author&query=Hillier%2C+D+J">D. John Hillier</a>, <a href="/search/astro-ph?searchtype=author&query=Larison%2C+C">Conor Larison</a>, <a href="/search/astro-ph?searchtype=author&query=Pakmor%2C+R">R眉diger Pakmor</a>, <a href="/search/astro-ph?searchtype=author&query=Temim%2C+T">Tea Temim</a>, <a href="/search/astro-ph?searchtype=author&query=Andrews%2C+J+E">Jennifer E. Andrews</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">Katie Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Badenes%2C+C">Carles Badenes</a>, <a href="/search/astro-ph?searchtype=author&query=Barna%2C+B">Barnabas Barna</a>, <a href="/search/astro-ph?searchtype=author&query=Bostroem%2C+K+A">K. Azalee Bostroem</a>, <a href="/search/astro-ph?searchtype=author&query=Newman%2C+M+J+B">Max J. Brenner Newman</a>, <a href="/search/astro-ph?searchtype=author&query=Brink%2C+T+G">Thomas G. Brink</a>, <a href="/search/astro-ph?searchtype=author&query=Bustamante-Rosell%2C+M+J">Mar铆a Jos茅 Bustamante-Rosell</a>, <a href="/search/astro-ph?searchtype=author&query=Camacho-Neves%2C+Y">Yssavo Camacho-Neves</a>, <a href="/search/astro-ph?searchtype=author&query=Clocchiatti%2C+A">Alejandro Clocchiatti</a>, <a href="/search/astro-ph?searchtype=author&query=Coulter%2C+D+A">David A. Coulter</a>, <a href="/search/astro-ph?searchtype=author&query=Davis%2C+K+W">Kyle W. Davis</a>, <a href="/search/astro-ph?searchtype=author&query=Deckers%2C+M">Maxime Deckers</a>, <a href="/search/astro-ph?searchtype=author&query=Dimitriadis%2C+G">Georgios Dimitriadis</a> , et al. (57 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.12449v1-abstract-short" style="display: inline;"> Nebular-phase observations of peculiar Type Ia supernovae (SNe Ia) provide important constraints on progenitor scenarios and explosion dynamics for both these rare SNe and the more common, cosmologically useful SNe Ia. We present observations from an extensive ground-based and space-based follow-up campaign to characterize SN 2022pul, a "super-Chandrasekhar" mass SN Ia (alternatively "03fg-like" S… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.12449v1-abstract-full').style.display = 'inline'; document.getElementById('2308.12449v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.12449v1-abstract-full" style="display: none;"> Nebular-phase observations of peculiar Type Ia supernovae (SNe Ia) provide important constraints on progenitor scenarios and explosion dynamics for both these rare SNe and the more common, cosmologically useful SNe Ia. We present observations from an extensive ground-based and space-based follow-up campaign to characterize SN 2022pul, a "super-Chandrasekhar" mass SN Ia (alternatively "03fg-like" SN), from before peak brightness to well into the nebular phase across optical to mid-infrared (MIR) wavelengths. The early rise of the light curve is atypical, exhibiting two distinct components, consistent with SN Ia ejecta interacting with dense carbon-oxygen rich circumstellar material (CSM). In the optical, SN 2022pul is most similar to SN 2012dn, having a low estimated peak luminosity ($M_{B}=-18.9$ mag) and high photospheric velocity relative to other 03fg-like SNe. In the nebular phase, SN 2022pul adds to the increasing diversity of the 03fg-like subclass. From 168 to 336 days after peak $B$-band brightness, SN 2022pul exhibits asymmetric and narrow emission from [O I] $位位6300,\ 6364$ (${\rm FWHM} \approx 2{,}000$ km s$^{-1}$), strong, broad emission from [Ca II] $位位7291,\ 7323$ (${\rm FWHM} \approx 7{,}300$ km s$^{-1}$), and a rapid Fe III to Fe II ionization change. Finally, we present the first-ever optical-to-mid-infrared (MIR) nebular spectrum of an 03fg-like SN Ia using data from JWST. In the MIR, strong lines of neon and argon, weak emission from stable nickel, and strong thermal dust emission (with $T \approx 500$ K), combined with prominent [O I] in the optical, suggest that SN 2022pul was produced by a white dwarf merger within carbon/oxygen-rich CSM. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.12449v1-abstract-full').style.display = 'none'; document.getElementById('2308.12449v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">23 pages, 11 figures, submitted to ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.11895">arXiv:2308.11895</a> <span> [<a href="https://arxiv.org/pdf/2308.11895">pdf</a>, <a href="https://arxiv.org/format/2308.11895">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> The Accretion History of EX Lup: A Century of Bursts, Outbursts, and Quiescence </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Wang%2C+M">Mu-Tian Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Herczeg%2C+G+J">Gregory J. Herczeg</a>, <a href="/search/astro-ph?searchtype=author&query=Liu%2C+H">Hui-Gen Liu</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+M">Min Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Johnstone%2C+D">Doug Johnstone</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+H">Ho-Gyu Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Walter%2C+F+M">Frederick M. Walter</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Pena%2C+C+C">Carlos Contreras Pena</a>, <a href="/search/astro-ph?searchtype=author&query=Lee%2C+J">Jeong-Eun Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Millward%2C+M">Mervyn Millward</a>, <a href="/search/astro-ph?searchtype=author&query=Pearce%2C+A">Andrew Pearce</a>, <a href="/search/astro-ph?searchtype=author&query=Monard%2C+B">Berto Monard</a>, <a href="/search/astro-ph?searchtype=author&query=Zhou%2C+L">Lihang Zhou</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.11895v1-abstract-short" style="display: inline;"> EX Lup is the archetype for the class of young stars that undergoes repeated accretion outbursts of $\sim 5$ mag at optical wavelengths and that last for months. Despite extensive monitoring that dates back 130 years, the accretion history of EX Lup remains mostly qualitative and has large uncertainties. We assess historical accretion rates of EX Lup by applying correlations between optical bright… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.11895v1-abstract-full').style.display = 'inline'; document.getElementById('2308.11895v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.11895v1-abstract-full" style="display: none;"> EX Lup is the archetype for the class of young stars that undergoes repeated accretion outbursts of $\sim 5$ mag at optical wavelengths and that last for months. Despite extensive monitoring that dates back 130 years, the accretion history of EX Lup remains mostly qualitative and has large uncertainties. We assess historical accretion rates of EX Lup by applying correlations between optical brightness and accretion, developed on multi-band magnitude photometry of the $\sim 2$ mag optical burst in 2022. Two distinct classes of bursts occur: major outbursts ($螖V\sim5$ mag) have year-long durations, are rare, reach accretion rates of $\dot{M}_{\rm acc}\sim10^{-7}~M_\odot~{\rm yr^{-1}}$ at peak, and have a total accreted mass of around 0.1 Earth masses. The characteristic bursts ($螖V\sim2$ mag) have durations of $\sim 2-3$ months, are more common, reach accretion rates of $\dot{M}_{\rm acc}\sim10^{-8}~M_\odot~{\rm yr^{-1}}$ at peak, and have a total accreted mass of around $10^{-3}$ Earth masses. The distribution of total accreted mass in the full set of bursts is poorly described by a power law, which suggests different driving causes behind the major outburst and characteristic bursts. The total mass accreted during two classes of bursts is around two times the masses accreted during quiescence. Our analysis of the light curves reveals a color-dependent time lag in the 2022 post-burst light curve, attributed to the presence of both hot and cool spots on the stellar surface. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.11895v1-abstract-full').style.display = 'none'; document.getElementById('2308.11895v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted by ApJ; 29 pages,19 figures, 6 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.01331">arXiv:2307.01331</a> <span> [<a href="https://arxiv.org/pdf/2307.01331">pdf</a>, <a href="https://arxiv.org/format/2307.01331">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202346162">10.1051/0004-6361/202346162 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> PM 1-322: new variable planetary nebula </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Paunzen%2C+E">E. Paunzen</a>, <a href="/search/astro-ph?searchtype=author&query=Bernhard%2C+K">K. Bernhard</a>, <a href="/search/astro-ph?searchtype=author&query=Budaj%2C+J">J. Budaj</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=H%C3%BCmmerich%2C+S">S. H眉mmerich</a>, <a href="/search/astro-ph?searchtype=author&query=Jones%2C+D">D. Jones</a>, <a href="/search/astro-ph?searchtype=author&query=Krticka%2C+J">J. Krticka</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.01331v1-abstract-short" style="display: inline;"> Spectra of planetary nebulae (PNe) are characterised by strong forbidden emission lines and often also by an infrared (IR) excess. A few PNe show dust obscuration events and/or harbour long-period binaries. Some post-asymptotic giant branch stars, symbiotic stars, or B[e] stars may feature similar characteristics. Recently, dust clouds eclipsing white dwarfs were also detected. We report the disco… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.01331v1-abstract-full').style.display = 'inline'; document.getElementById('2307.01331v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.01331v1-abstract-full" style="display: none;"> Spectra of planetary nebulae (PNe) are characterised by strong forbidden emission lines and often also by an infrared (IR) excess. A few PNe show dust obscuration events and/or harbour long-period binaries. Some post-asymptotic giant branch stars, symbiotic stars, or B[e] stars may feature similar characteristics. Recently, dust clouds eclipsing white dwarfs were also detected. We report the discovery of an object with a very peculiar variability pattern that bears signatures compatible with the above-mentioned classes of objects. The object is ZTFJ201451.59+120353.4 and identifies with PM 1-322. The object was discovered in Zwicky Transient Facility archival data and investigated with historical and newly obtained photometric and spectroscopic observations. The ZTF r and g data show a one magnitude deep, eclipse-like event with a duration of about half a year that occurred in 2022. The variability pattern of the star is further characterised by several dimming events in the optical region that are accompanied by simultaneous brightenings in the red and IR regions. Apart from that, two fast eruption-like events were recorded in ZTF r data. Archival data from WISE indicate long-term variability with a possible period of 6 or 12 yr. Our follow-up time series photometry reveals a stochastic short-term variability with an amplitude of about 0.1 mag on a timescale of about one hour. The spectral energy distribution is dominated by IR radiation. Our high-resolution spectroscopy shows strong forbidden emission lines from highly ionised species and symmetric double-peaked emission in Halpha, which is very different from what is seen in earlier spectra obtained in 2007. Several explanatory scenarios are presented. Our most likely interpretation is that our target object involves a hot central star surrounded by gaseous and dusty disks, an extended nebula, and a possible companion star. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.01331v1-abstract-full').style.display = 'none'; document.getElementById('2307.01331v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 8 figures, 2 tables, accepted for publication in Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 676, A88 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.00258">arXiv:2307.00258</a> <span> [<a href="https://arxiv.org/pdf/2307.00258">pdf</a>, <a href="https://arxiv.org/ps/2307.00258">ps</a>, <a href="https://arxiv.org/format/2307.00258">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> ASASSN-22ak: La Belle au bois dormant in a hydrogen-depleted dwarf nova? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Monard%2C+B">Berto Monard</a>, <a href="/search/astro-ph?searchtype=author&query=Stubbings%2C+R">Rod Stubbings</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.00258v1-abstract-short" style="display: inline;"> ASASSN-22ak is a transient discovered by the All-Sky Automated Survey for Supernovae and by Gaia in 2022 January. Although this object had been in deep quiescence at least for seven years before this outburst, it has been showing relatively regular long (35-40 d) outbursts with intervals of 132-188 d after the 2022 January outburst. This "waking up" phenomenon appears similar to the very unusual (… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.00258v1-abstract-full').style.display = 'inline'; document.getElementById('2307.00258v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.00258v1-abstract-full" style="display: none;"> ASASSN-22ak is a transient discovered by the All-Sky Automated Survey for Supernovae and by Gaia in 2022 January. Although this object had been in deep quiescence at least for seven years before this outburst, it has been showing relatively regular long (35-40 d) outbursts with intervals of 132-188 d after the 2022 January outburst. This "waking up" phenomenon appears similar to the very unusual (hydrogen-rich) WZ Sge star V3101 Cyg. Time-resolved photometry during the 2023 outburst detected low-amplitude (0.05 mag) superhumps with a period of 0.042876(3) d. ASASSN-22ak appears to be very similar to CRTS J112253.3-111037, which is known to have a very low mass ratio and is considered to be an object evolving close to AM CVn stars as inferred from the low hydrogen and high helium content. ASASSN-22ak is likely yet another object having an evolved core and strongly depleted hydrogen in the secondary. The case of ASASSN-22ak strengthens the idea that a considerable fraction of AM CVn stars are formed from evolved cataclysmic variables. Both ASASSN-22ak and V3101 Cyg before the initial outbursts were probably in dormant states with low quiescent viscosity or low mass-transfer rates. The current "high" states of ASASSN-22ak and V3101 Cyg may have been induced by radiation during the initial outburst or these objects are simply returning to ordinary states, either in terms of quiescent viscosity or mass-transfer rates. We also provide updated superhump period and estimated mass ratio for CRTS J112253.3-111037. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.00258v1-abstract-full').style.display = 'none'; document.getElementById('2307.00258v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 6 figures, VSOLJ Variable Star Bulletin No. 120</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.15107">arXiv:2306.15107</a> <span> [<a href="https://arxiv.org/pdf/2306.15107">pdf</a>, <a href="https://arxiv.org/format/2306.15107">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ace2cb">10.3847/1538-4357/ace2cb <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Modeling the Multiwavelength Evolution of the V960 Mon System </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Carvalho%2C+A+S">Adolfo S. Carvalho</a>, <a href="/search/astro-ph?searchtype=author&query=Hillenbrand%2C+L+A">Lynne A. Hillenbrand</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Dvorak%2C+S">Shawn Dvorak</a>, <a href="/search/astro-ph?searchtype=author&query=Sitko%2C+M">Michael Sitko</a>, <a href="/search/astro-ph?searchtype=author&query=Russell%2C+R+W">Ray W. Russell</a>, <a href="/search/astro-ph?searchtype=author&query=Hammond%2C+V">Victoria Hammond</a>, <a href="/search/astro-ph?searchtype=author&query=Connelley%2C+M">Michael Connelley</a>, <a href="/search/astro-ph?searchtype=author&query=Ashley%2C+M+C+B">Michael C. B. Ashley</a>, <a href="/search/astro-ph?searchtype=author&query=Hankins%2C+M+J">Matthew J. Hankins</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.15107v1-abstract-short" style="display: inline;"> We study the evolution of the FU Ori object V960 Mon since its outburst, using available multi-wavelength photometric time series over 8 years, complemented by several epochs of moderate-dispersion spectrophotometry. We find that the source fading can be well-described by a decrease in the temperature of the inner disk, which results from a combination of decreasing accretion rate and increasing i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.15107v1-abstract-full').style.display = 'inline'; document.getElementById('2306.15107v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.15107v1-abstract-full" style="display: none;"> We study the evolution of the FU Ori object V960 Mon since its outburst, using available multi-wavelength photometric time series over 8 years, complemented by several epochs of moderate-dispersion spectrophotometry. We find that the source fading can be well-described by a decrease in the temperature of the inner disk, which results from a combination of decreasing accretion rate and increasing inner disk radius. We model the system with a disk atmosphere model that produces the observed variations in multi-band photometry (this paper) and high resolution spectral lines (a companion paper). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.15107v1-abstract-full').style.display = 'none'; document.getElementById('2306.15107v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 13 figures, 2 tables, Accepted to ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.17960">arXiv:2303.17960</a> <span> [<a href="https://arxiv.org/pdf/2303.17960">pdf</a>, <a href="https://arxiv.org/ps/2303.17960">ps</a>, <a href="https://arxiv.org/format/2303.17960">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/pasj/psad023">10.1093/pasj/psad023 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> 2021 superoutburst of WZ Sge-type dwarf nova V627 Pegasi lacks an early superhump phase </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Tampo%2C+Y">Yusuke Tampo</a>, <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Kojiguchi%2C+N">Naoto Kojiguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Shugarov%2C+S+Y">Sergey Yu. Shugarov</a>, <a href="/search/astro-ph?searchtype=author&query=Itoh%2C+H">Hiroshi Itoh</a>, <a href="/search/astro-ph?searchtype=author&query=Matsumoto%2C+K">Katsura Matsumoto</a>, <a href="/search/astro-ph?searchtype=author&query=Nakagawa%2C+M">Momoka Nakagawa</a>, <a href="/search/astro-ph?searchtype=author&query=Nishida%2C+Y">Yukitaka Nishida</a>, <a href="/search/astro-ph?searchtype=author&query=Richmond%2C+M">Michael Richmond</a>, <a href="/search/astro-ph?searchtype=author&query=Shibata%2C+M">Masaaki Shibata</a>, <a href="/search/astro-ph?searchtype=author&query=Ito%2C+J">Junpei Ito</a>, <a href="/search/astro-ph?searchtype=author&query=Kokhirova%2C+G">Gulchehra Kokhirova</a>, <a href="/search/astro-ph?searchtype=author&query=Rakhmatullaeva%2C+F">Firuza Rakhmatullaeva</a>, <a href="/search/astro-ph?searchtype=author&query=Tordai%2C+T">Tam谩s Tordai</a>, <a href="/search/astro-ph?searchtype=author&query=Kiyota%2C+S">Seiichiro Kiyota</a>, <a href="/search/astro-ph?searchtype=author&query=Ruiz%2C+J">Javier Ruiz</a>, <a href="/search/astro-ph?searchtype=author&query=Dubovsky%2C+P+A">Pavol A. Dubovsky</a>, <a href="/search/astro-ph?searchtype=author&query=Medulka%2C+T">Tom谩拧 Medulka</a>, <a href="/search/astro-ph?searchtype=author&query=Pavlenko%2C+E+P">Elena P. Pavlenko</a>, <a href="/search/astro-ph?searchtype=author&query=Antonyuk%2C+O+I">Oksana I. Antonyuk</a>, <a href="/search/astro-ph?searchtype=author&query=Sosnovskij%2C+A+A">Aleksei A. Sosnovskij</a>, <a href="/search/astro-ph?searchtype=author&query=Baklanov%2C+A+V">Aleksei V. Baklanov</a>, <a href="/search/astro-ph?searchtype=author&query=Krushevska%2C+V">Viktoriia Krushevska</a>, <a href="/search/astro-ph?searchtype=author&query=Vanmunster%2C+T">Tonny Vanmunster</a>, <a href="/search/astro-ph?searchtype=author&query=Brincat%2C+S+M">Stephen M. Brincat</a> , et al. (5 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.17960v1-abstract-short" style="display: inline;"> Superoutbursts in WZ Sge-type dwarf novae (DNe) are characterized by both early superhumps and ordinary superhumps originating from the 2:1 and 3:1 resonances, respectively. However, some WZ Sge-type DNe show a superoutburst lacking early superhumps; it is not well established how these differ from superoutbursts with an early superhump phase. We report time-resolved photometric observations of th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.17960v1-abstract-full').style.display = 'inline'; document.getElementById('2303.17960v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.17960v1-abstract-full" style="display: none;"> Superoutbursts in WZ Sge-type dwarf novae (DNe) are characterized by both early superhumps and ordinary superhumps originating from the 2:1 and 3:1 resonances, respectively. However, some WZ Sge-type DNe show a superoutburst lacking early superhumps; it is not well established how these differ from superoutbursts with an early superhump phase. We report time-resolved photometric observations of the WZ Sge-type DN V627 Peg during its 2021 superoutburst. The detection of ordinary superhumps before the superoutburst peak highlights that this 2021 superoutburst of V627 Peg, like that {in} 2014, did not feature an early superhump phase. The duration of stage B superhumps was slightly longer in the 2010 superoutburst accompanying early superhumps than that in the 2014 and 2021 superoutbursts which lacked early superhumps. This result suggests that an accretion disk experiencing the 2:1 resonance may have a larger mass at the inner part of the disk and hence take more time for the inner disk to become eccentric. The presence of a precursor outburst in the 2021 superoutburst suggests that the maximum disk radius should be smaller than that of the 2014 superoutburst, even though the duration of quiescence was longer than that before the 2021 superoutburst. This could be accomplished if the 2021 superoutburst was triggered as an inside-out outburst or if the mass transfer rate in quiescence changes by a factor of two, suggesting that the outburst mechanism and quiescence state of WZ Sge-type DNe may have more variety than ever thought. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.17960v1-abstract-full').style.display = 'none'; document.getElementById('2303.17960v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 5 figures, 1 table, accepted for publication in PASJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.09782">arXiv:2302.09782</a> <span> [<a href="https://arxiv.org/pdf/2302.09782">pdf</a>, <a href="https://arxiv.org/ps/2302.09782">ps</a>, <a href="https://arxiv.org/format/2302.09782">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> On the orbital period of the dwarf nova CW Mon </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.09782v1-abstract-short" style="display: inline;"> CW Mon is a relatively bright and nearby SS Cyg-type dwarf nova frequently used in detailed analysis of cataclysmic variables and statistical studies. Using Transiting Exoplanet Survey Satellite (TESS) observations, we found that the orbital period is different from what has been adopted. Using the combined data (TESS, the Zwicky Transient Facility data and VSNET campaigns), we updated the period… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.09782v1-abstract-full').style.display = 'inline'; document.getElementById('2302.09782v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.09782v1-abstract-full" style="display: none;"> CW Mon is a relatively bright and nearby SS Cyg-type dwarf nova frequently used in detailed analysis of cataclysmic variables and statistical studies. Using Transiting Exoplanet Survey Satellite (TESS) observations, we found that the orbital period is different from what has been adopted. Using the combined data (TESS, the Zwicky Transient Facility data and VSNET campaigns), we updated the period to be 0.19346802(4) d. The previously adopted period of 0.1766 d turned out to be its 2-day alias, probably introduced by a confusion between the two maxima/minima of the ellipsoidal variations. We confirmed that the object showed grazing eclipses during the 2016 and 2002 outbursts, and also in quiescence before and after the 2016 outburst. These eclipses were not necessarily always present and were not remarkable during some past outbursts and in the TESS data. The presence/absence of eclipses may be related to the disk radius or the brightness of the outer part of the disk. A 37-min quasi-period oscillation (QPO) signal was reported during the 2002 outburst. Combined with a recent report of the detection of QPOs around the peaks of long outbursts of a dwarf nova, we suspect that such QPOs during long outbursts may have been excited when the accretion disk reaches the maximum radius, the tidal truncation radius as being a possibility. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.09782v1-abstract-full').style.display = 'none'; document.getElementById('2302.09782v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pagas, 5 figures, VSOLJ Variable Star Bulletin No. 110</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.02696">arXiv:2302.02696</a> <span> [<a href="https://arxiv.org/pdf/2302.02696">pdf</a>, <a href="https://arxiv.org/format/2302.02696">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stad407">10.1093/mnras/stad407 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A survey for variable young stars with small telescopes: VI -- Analysis of the outbursting Be stars NSW284, Gaia19eyy, and VES263 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Froebrich%2C+D">Dirk Froebrich</a>, <a href="/search/astro-ph?searchtype=author&query=Hillenbrand%2C+L+A">Lynne A. Hillenbrand</a>, <a href="/search/astro-ph?searchtype=author&query=Herbert%2C+C">Carys Herbert</a>, <a href="/search/astro-ph?searchtype=author&query=De%2C+K">Kishalay De</a>, <a href="/search/astro-ph?searchtype=author&query=Eisl%C3%B6ffel%2C+J">Jochen Eisl枚ffel</a>, <a href="/search/astro-ph?searchtype=author&query=Campbell-White%2C+J">Justyn Campbell-White</a>, <a href="/search/astro-ph?searchtype=author&query=Kahar%2C+R">Ruhee Kahar</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Urtly%2C+T">Thomas Urtly</a>, <a href="/search/astro-ph?searchtype=author&query=Popowicz%2C+A">Adam Popowicz</a>, <a href="/search/astro-ph?searchtype=author&query=Bernacki%2C+K">Krzysztof Bernacki</a>, <a href="/search/astro-ph?searchtype=author&query=Malcher%2C+A">Andrzej Malcher</a>, <a href="/search/astro-ph?searchtype=author&query=Lasota%2C+S">Slawomir Lasota</a>, <a href="/search/astro-ph?searchtype=author&query=Fiolka%2C+J">Jerzy Fiolka</a>, <a href="/search/astro-ph?searchtype=author&query=Jozwik-Wabik%2C+P">Piotr Jozwik-Wabik</a>, <a href="/search/astro-ph?searchtype=author&query=Dubois%2C+F">Franky Dubois</a>, <a href="/search/astro-ph?searchtype=author&query=Logie%2C+L">Ludwig Logie</a>, <a href="/search/astro-ph?searchtype=author&query=Rau%2C+S">Steve Rau</a>, <a href="/search/astro-ph?searchtype=author&query=Phillips%2C+M">Mark Phillips</a>, <a href="/search/astro-ph?searchtype=author&query=Fleming%2C+G">George Fleming</a>, <a href="/search/astro-ph?searchtype=author&query=Farf%C3%A1n%2C+R+G">Rafael Gonzalez Farf谩n</a>, <a href="/search/astro-ph?searchtype=author&query=Alfaro%2C+F+C+S">Francisco C. Sold谩n Alfaro</a>, <a href="/search/astro-ph?searchtype=author&query=Nelson%2C+T">Tim Nelson</a>, <a href="/search/astro-ph?searchtype=author&query=Futcher%2C+S+R+L">Stephen R. L. Futcher</a>, <a href="/search/astro-ph?searchtype=author&query=Rolfe%2C+S+M">Samantha M. Rolfe</a> , et al. (22 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.02696v1-abstract-short" style="display: inline;"> This paper is one in a series reporting results from small telescope observations of variable young stars. Here, we study the repeating outbursts of three likely Be stars based on long-term optical, near-infrared, and mid-infrared photometry for all three objects, along with follow-up spectra for two of the three. The sources are characterised as rare, truly regularly outbursting Be stars. We inte… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.02696v1-abstract-full').style.display = 'inline'; document.getElementById('2302.02696v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.02696v1-abstract-full" style="display: none;"> This paper is one in a series reporting results from small telescope observations of variable young stars. Here, we study the repeating outbursts of three likely Be stars based on long-term optical, near-infrared, and mid-infrared photometry for all three objects, along with follow-up spectra for two of the three. The sources are characterised as rare, truly regularly outbursting Be stars. We interpret the photometric data within a framework for modelling light curve morphology, and find that the models correctly predict the burst shapes, including their larger amplitudes and later peaks towards longer wavelengths. We are thus able to infer the start and end times of mass loading into the circumstellar disks of these stars. The disk sizes are typically 3-6 times the areas of the central star. The disk temperatures are ~40%, and the disk luminosities are ~10% of those of the central Be star, respectively. The available spectroscopy is consistent with inside-out evolution of the disk. Higher excitation lines have larger velocity widths in their double-horned shaped emission profiles. Our observations and analysis support the decretion disk model for outbursting Be stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.02696v1-abstract-full').style.display = 'none'; document.getElementById('2302.02696v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication by MNRAS. 20 pages, 11 figures, 2 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.09630">arXiv:2208.09630</a> <span> [<a href="https://arxiv.org/pdf/2208.09630">pdf</a>, <a href="https://arxiv.org/format/2208.09630">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202244498">10.1051/0004-6361/202244498 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Persistent nuclear burning in Nova Sgr 2016 N.4 (= V5856 Sgr = ASASSN-16ma) six years past its outburst </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Munari%2C+U">U. Munari</a>, <a href="/search/astro-ph?searchtype=author&query=Masetti%2C+N">N. Masetti</a>, <a href="/search/astro-ph?searchtype=author&query=Walter%2C+F+M">F. M. Walter</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+R+E">R. E. Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Frigo%2C+A">A. Frigo</a>, <a href="/search/astro-ph?searchtype=author&query=Valisa%2C+P">P. Valisa</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.09630v1-abstract-short" style="display: inline;"> We report on the fast Nova Sgr 2016 N.4 being surprisingly trapped in a long-lasting and bright plateau (Delta I >= 10 mag above quiescence) six years past the nova eruption. Very few other novae experience a similar occurrence. We carried out an intensive observing campaign collecting daily BVRI photometry and monthly high-resolution optical spectroscopy, and observed the nova in ultraviolet and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.09630v1-abstract-full').style.display = 'inline'; document.getElementById('2208.09630v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.09630v1-abstract-full" style="display: none;"> We report on the fast Nova Sgr 2016 N.4 being surprisingly trapped in a long-lasting and bright plateau (Delta I >= 10 mag above quiescence) six years past the nova eruption. Very few other novae experience a similar occurrence. We carried out an intensive observing campaign collecting daily BVRI photometry and monthly high-resolution optical spectroscopy, and observed the nova in ultraviolet and X-rays with Swift satellite at five distinct epochs. The bolometric luminosity radiated during the plateau is ~4200 Lsun (scaled to the distance of the Galactic Bulge), corresponding to stable nuclear burning on a 0.6 Msun white dwarf. A stable wind is blown off at FWZI~1600 km/s, with episodic reinforcement of a faster FWZI~3400 km/s mass loss, probably oriented along the polar directions. The collision of these winds could power the emission detected in X-rays. The burning shell has an outer radius of ~25 Rsun at which the effective temperature is ~7600 K, values similar to those of a F0 II/Ib bright giant. The Delta m < 1 mag variability displayed during the plateau is best described as chaotic, with the irregular appearance of quasi-periodic oscillations with a periodicity of 15-17 days. A limited amount of dust (~3x10^(-11) Msun) continuously condenses at T(dust)~1200 K in the outflowing wind, radiating L(dust)~52 Lsun. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.09630v1-abstract-full').style.display = 'none'; document.getElementById('2208.09630v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 667, A7 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.04251">arXiv:2208.04251</a> <span> [<a href="https://arxiv.org/pdf/2208.04251">pdf</a>, <a href="https://arxiv.org/ps/2208.04251">ps</a>, <a href="https://arxiv.org/format/2208.04251">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/pasj/psac068">10.1093/pasj/psac068 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> PNV J00444033+4113068: early superhumps with 0.7 mag amplitude and non-red color </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Tampo%2C+Y">Yusuke Tampo</a>, <a href="/search/astro-ph?searchtype=author&query=Isogai%2C+K">Keisuke Isogai</a>, <a href="/search/astro-ph?searchtype=author&query=Kojiguchi%2C+N">Naoto Kojiguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Uemura%2C+M">Makoto Uemura</a>, <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Tordai%2C+T">Tam谩s Tordai</a>, <a href="/search/astro-ph?searchtype=author&query=Vanmunster%2C+T">Tonny Vanmunster</a>, <a href="/search/astro-ph?searchtype=author&query=Itoh%2C+H">Hiroshi Itoh</a>, <a href="/search/astro-ph?searchtype=author&query=Dubovsky%2C+P+A">Pavol A. Dubovsky</a>, <a href="/search/astro-ph?searchtype=author&query=Medulka%2C+T">Tom谩拧 Medulka</a>, <a href="/search/astro-ph?searchtype=author&query=Sano%2C+Y">Yasuo Sano</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Taguchi%2C+K">Kenta Taguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Maehara%2C+H">Hiroyuki Maehara</a>, <a href="/search/astro-ph?searchtype=author&query=Ito%2C+J">Junpei Ito</a>, <a href="/search/astro-ph?searchtype=author&query=Nogam%2C+D">Daisaku Nogam</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.04251v1-abstract-short" style="display: inline;"> In the first days of WZ Sge-type dwarf nova (DN) outbursts, the 2:1 resonance induces a spiral arm structure in the accretion disk, which is observed as early superhumps in optical light curves. This paper reports our optical observations of an eclipsing WZ Sge-type DN PNV J00444033+4113068 during its 2021 superoutburst with the 3.8m Seimei telescope and through VSNET collaboration. The eclipse an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.04251v1-abstract-full').style.display = 'inline'; document.getElementById('2208.04251v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.04251v1-abstract-full" style="display: none;"> In the first days of WZ Sge-type dwarf nova (DN) outbursts, the 2:1 resonance induces a spiral arm structure in the accretion disk, which is observed as early superhumps in optical light curves. This paper reports our optical observations of an eclipsing WZ Sge-type DN PNV J00444033+4113068 during its 2021 superoutburst with the 3.8m Seimei telescope and through VSNET collaboration. The eclipse analysis gave its orbital period as 0.055425534(1) d. Our observations confirmed early superhumps with an amplitude of 0.7 mag, the largest amplitude among known WZ Sge-type DNe. More interestingly, its early superhumps became the reddest around their secondary minimum, whereas other WZ Sge-type DNe show the reddest color around the early superhump maximum. The spectrum around the peak of the outburst showed the double-peaked emission lines of He II 4686脜~ and H$伪$ with a peak separation of $\ge 700$ km/s, supporting a very high-inclination system. With the early superhump mapping, the unique profile and color of the early superhump of PNV J00444033+4113068 are successfully reproduced by the accretion disk with vertically extended double arm structure. Therefore, the large amplitude and unique color behavior of the early superhumps in PNV J00444033+4113068 can be explained by the 2:1 resonance model along with other WZ Sge-type DNe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.04251v1-abstract-full').style.display = 'none'; document.getElementById('2208.04251v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 4 figures, 1 table, accepted for publication in PASJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.00181">arXiv:2207.00181</a> <span> [<a href="https://arxiv.org/pdf/2207.00181">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/ac9ebe">10.3847/2041-8213/ac9ebe <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Periodic Signals of Nova V1674 Herculis (2021) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Patterson%2C+J">Joseph Patterson</a>, <a href="/search/astro-ph?searchtype=author&query=Epstein-Martin%2C+M">Marguerite Epstein-Martin</a>, <a href="/search/astro-ph?searchtype=author&query=Enenstein%2C+J">Josie Enenstein</a>, <a href="/search/astro-ph?searchtype=author&query=Kemp%2C+J">Jonathan Kemp</a>, <a href="/search/astro-ph?searchtype=author&query=Sabo%2C+R">Richard Sabo</a>, <a href="/search/astro-ph?searchtype=author&query=Cooney%2C+W">Walt Cooney</a>, <a href="/search/astro-ph?searchtype=author&query=Vanmunster%2C+T">Tonny Vanmunster</a>, <a href="/search/astro-ph?searchtype=author&query=Dubovsky%2C+P">Pavol Dubovsky</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Myers%2C+G">Gordon Myers</a>, <a href="/search/astro-ph?searchtype=author&query=Lemay%2C+D">Damien Lemay</a>, <a href="/search/astro-ph?searchtype=author&query=Sokolovsky%2C+K">Kirill Sokolovsky</a>, <a href="/search/astro-ph?searchtype=author&query=Collins%2C+D">Donald Collins</a>, <a href="/search/astro-ph?searchtype=author&query=Campbell%2C+T">Tut Campbell</a>, <a href="/search/astro-ph?searchtype=author&query=Roberts%2C+G">George Roberts</a>, <a href="/search/astro-ph?searchtype=author&query=Richmond%2C+M">Michael Richmond</a>, <a href="/search/astro-ph?searchtype=author&query=Brincat%2C+S">Stephen Brincat</a>, <a href="/search/astro-ph?searchtype=author&query=Ulowetz%2C+J">Joseph Ulowetz</a>, <a href="/search/astro-ph?searchtype=author&query=Dvorak%2C+S">Shawn Dvorak</a>, <a href="/search/astro-ph?searchtype=author&query=Tordai%2C+T">Tamas Tordai</a>, <a href="/search/astro-ph?searchtype=author&query=Dufoer%2C+S">Sjoerd Dufoer</a>, <a href="/search/astro-ph?searchtype=author&query=Cahaly%2C+A">Andrew Cahaly</a>, <a href="/search/astro-ph?searchtype=author&query=Galdies%2C+C">Charles Galdies</a>, <a href="/search/astro-ph?searchtype=author&query=Goff%2C+B">Bill Goff</a>, <a href="/search/astro-ph?searchtype=author&query=Wilkin%2C+F">Francis Wilkin</a> , et al. (2 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.00181v1-abstract-short" style="display: inline;"> We present time-series photometry during eruption of the extremely fast nova V1674 Herculis (Nova Her 2021). The 2021 light curve showed periodic signals at 0.152921(3) d and 501.486(5) s, which we interpret as respectively the orbital and white dwarf spin-periods in the underlying binary. We also detected a sideband signal at the /difference/ frequency between these two clocks. During the first 1… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.00181v1-abstract-full').style.display = 'inline'; document.getElementById('2207.00181v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.00181v1-abstract-full" style="display: none;"> We present time-series photometry during eruption of the extremely fast nova V1674 Herculis (Nova Her 2021). The 2021 light curve showed periodic signals at 0.152921(3) d and 501.486(5) s, which we interpret as respectively the orbital and white dwarf spin-periods in the underlying binary. We also detected a sideband signal at the /difference/ frequency between these two clocks. During the first 15 days of outburst, the spin-period appears to have increased by 0.014(1)%. This increase probably arose from the sudden loss of high-angular-momentum gas ("the nova explosion") from the rotating, magnetic white dwarf. Both periodic signals appeared remarkably early in the outburst, which we attribute to the extreme speed with which the nova evolved (and became transparent to radiation from the inner binary). After that very fast initial increase of ~71 ms, the spin-period commenced a steady decrease of ~160 ms/year -- about 100x faster than usually seen in intermediate polars. This is probably due to high accretion torques from very high mass-transfer rates, which might be common when low-mass donor stars are strongly irradiated by a nova outburst. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.00181v1-abstract-full').style.display = 'none'; document.getElementById('2207.00181v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">PDF, 10 pages, 1 table, 3 figures; in preparation; more info at http://cbastro.org/</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.00813">arXiv:2206.00813</a> <span> [<a href="https://arxiv.org/pdf/2206.00813">pdf</a>, <a href="https://arxiv.org/format/2206.00813">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2041-8213/ac7b2d">10.3847/2041-8213/ac7b2d <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Two Candidate KH 15D-like Systems from the Zwicky Transient Facility </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zhu%2C+W">Wei Zhu</a>, <a href="/search/astro-ph?searchtype=author&query=Bernhard%2C+K">Klaus Bernhard</a>, <a href="/search/astro-ph?searchtype=author&query=Dai%2C+F">Fei Dai</a>, <a href="/search/astro-ph?searchtype=author&query=Fang%2C+M">Min Fang</a>, <a href="/search/astro-ph?searchtype=author&query=Zanazzi%2C+J+J">J. J. Zanazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Zang%2C+W">Weicheng Zang</a>, <a href="/search/astro-ph?searchtype=author&query=Dong%2C+S">Subo Dong</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Gan%2C+T">Tianjun Gan</a>, <a href="/search/astro-ph?searchtype=author&query=Wu%2C+Z">Zexuan Wu</a>, <a href="/search/astro-ph?searchtype=author&query=Poon%2C+M">Michael Poon</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2206.00813v2-abstract-short" style="display: inline;"> KH 15D contains a circumbinary disk that is tilted relative to the orbital plane of the central binary. The precession of the disk and the orbital motion of the binary together produce rich phenomena in the photometric light curve. In this work, we present the discovery and preliminary analysis of two objects that resemble the key features of KH 15D from the Zwicky Transient Facility. These new ob… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.00813v2-abstract-full').style.display = 'inline'; document.getElementById('2206.00813v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.00813v2-abstract-full" style="display: none;"> KH 15D contains a circumbinary disk that is tilted relative to the orbital plane of the central binary. The precession of the disk and the orbital motion of the binary together produce rich phenomena in the photometric light curve. In this work, we present the discovery and preliminary analysis of two objects that resemble the key features of KH 15D from the Zwicky Transient Facility. These new objects, Bernhard-1 and Bernhard-2, show large-amplitude ($>1.5\,$mag), long-duration (more than tens of days), and periodic dimming events. A one-sided screen model is developed to model the photometric behaviour of these objects, the physical interpretation of which is a tilted, warped circumbinary disk occulting the inner binary. Changes in the object light curves suggest potential precession periods over timescales longer than 10 years. Additional photometric and spectroscopic observations are encouraged to better understand the nature of these interesting systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.00813v2-abstract-full').style.display = 'none'; document.getElementById('2206.00813v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 5 figures, 2 tables, accepted to ApJ Letters</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2202.08365">arXiv:2202.08365</a> <span> [<a href="https://arxiv.org/pdf/2202.08365">pdf</a>, <a href="https://arxiv.org/format/2202.08365">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/ac5682">10.3847/1538-4357/ac5682 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Investigating the low-flux states in six Intermediate Polars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Covington%2C+A+E">Ava E. Covington</a>, <a href="/search/astro-ph?searchtype=author&query=Shaw%2C+A+W">Aarran W. Shaw</a>, <a href="/search/astro-ph?searchtype=author&query=Mukai%2C+K">Koji Mukai</a>, <a href="/search/astro-ph?searchtype=author&query=Littlefield%2C+C">Colin Littlefield</a>, <a href="/search/astro-ph?searchtype=author&query=Heinke%2C+C+O">Craig O. Heinke</a>, <a href="/search/astro-ph?searchtype=author&query=Plotkin%2C+R+M">Richard M. Plotkin</a>, <a href="/search/astro-ph?searchtype=author&query=Barrett%2C+D">Doug Barrett</a>, <a href="/search/astro-ph?searchtype=author&query=Boardman%2C+J">James Boardman</a>, <a href="/search/astro-ph?searchtype=author&query=Boyd%2C+D">David Boyd</a>, <a href="/search/astro-ph?searchtype=author&query=Brincat%2C+S+M">Stephen M. Brincat</a>, <a href="/search/astro-ph?searchtype=author&query=Carstens%2C+R">Rolf Carstens</a>, <a href="/search/astro-ph?searchtype=author&query=Collins%2C+D+F">Donald F. Collins</a>, <a href="/search/astro-ph?searchtype=author&query=Cook%2C+L+M">Lewis M. Cook</a>, <a href="/search/astro-ph?searchtype=author&query=Cooney%2C+W+R">Walter R. Cooney</a>, <a href="/search/astro-ph?searchtype=author&query=Fern%C3%A1ndez%2C+D+C">David Cejudo Fern谩ndez</a>, <a href="/search/astro-ph?searchtype=author&query=Dufoer%2C+S">Sjoerd Dufoer</a>, <a href="/search/astro-ph?searchtype=author&query=Dvorak%2C+S">Shawn Dvorak</a>, <a href="/search/astro-ph?searchtype=author&query=Galdies%2C+C">Charles Galdies</a>, <a href="/search/astro-ph?searchtype=author&query=Goff%2C+W">William Goff</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Johnston%2C+S">Steve Johnston</a>, <a href="/search/astro-ph?searchtype=author&query=Jones%2C+J">Jim Jones</a>, <a href="/search/astro-ph?searchtype=author&query=Menzies%2C+K">Kenneth Menzies</a>, <a href="/search/astro-ph?searchtype=author&query=Monard%2C+L+A+G">Libert A. G. Monard</a>, <a href="/search/astro-ph?searchtype=author&query=Morelle%2C+E">Etienne Morelle</a> , et al. (8 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2202.08365v2-abstract-short" style="display: inline;"> We present optical photometry of six intermediate polars that exhibit transitions to a low-flux state. For four of these systems, DW Cnc, V515 And, V1223 Sgr and RX J2133.7+5107, we are able to perform timing analysis in and out of the low states. We find that, for DW Cnc and V515 And, the dominant periodicities in the light curves change as the flux decreases, indicating a change in the sources'… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.08365v2-abstract-full').style.display = 'inline'; document.getElementById('2202.08365v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2202.08365v2-abstract-full" style="display: none;"> We present optical photometry of six intermediate polars that exhibit transitions to a low-flux state. For four of these systems, DW Cnc, V515 And, V1223 Sgr and RX J2133.7+5107, we are able to perform timing analysis in and out of the low states. We find that, for DW Cnc and V515 And, the dominant periodicities in the light curves change as the flux decreases, indicating a change in the sources' accretion properties as they transition to the low state. For V1223 Sgr we find that the variability is almost completely quenched at the lowest flux, but do not find evidence for a changing accretion geometry. For RX J2133.7+5107, the temporal properties do not change in the low state, but we do see a period of enhanced accretion that is coincident with increased variability on the beat frequency, which we do not associate with a change in the accretion mechanisms in the system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.08365v2-abstract-full').style.display = 'none'; document.getElementById('2202.08365v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 February, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 February, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 10 figures, accepted for publication in ApJ. The authors recommend downloading the PDF of this paper, as it takes a while to render online</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.10808">arXiv:2112.10808</a> <span> [<a href="https://arxiv.org/pdf/2112.10808">pdf</a>, <a href="https://arxiv.org/format/2112.10808">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> Radial Distribution of the Dust Comae of Comets 45P/Honda-Mrkos-Pajduus谩kov谩 and 46P/Wirtanen </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lejoly%2C+C">C. Lejoly</a>, <a href="/search/astro-ph?searchtype=author&query=Harris%2C+W">W. Harris</a>, <a href="/search/astro-ph?searchtype=author&query=Samarasinha%2C+N">N. Samarasinha</a>, <a href="/search/astro-ph?searchtype=author&query=Mueller%2C+B+E+A">B. E. A. Mueller</a>, <a href="/search/astro-ph?searchtype=author&query=Howell%2C+E">E. Howell</a>, <a href="/search/astro-ph?searchtype=author&query=Bodnarik%2C+J">J. Bodnarik</a>, <a href="/search/astro-ph?searchtype=author&query=Springmann%2C+A">A. Springmann</a>, <a href="/search/astro-ph?searchtype=author&query=Kareta%2C+T">T. Kareta</a>, <a href="/search/astro-ph?searchtype=author&query=Sharkey%2C+B">B. Sharkey</a>, <a href="/search/astro-ph?searchtype=author&query=Noonan%2C+J">J. Noonan</a>, <a href="/search/astro-ph?searchtype=author&query=Bedin%2C+L+R">L. R. Bedin</a>, <a href="/search/astro-ph?searchtype=author&query=Bosch%2C+J+-">J. -G. Bosch</a>, <a href="/search/astro-ph?searchtype=author&query=Brosio%2C+A">A. Brosio</a>, <a href="/search/astro-ph?searchtype=author&query=Bryssinck%2C+E">E. Bryssinck</a>, <a href="/search/astro-ph?searchtype=author&query=de+Vanssay%2C+J+-">J. -B. de Vanssay</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Ivanova%2C+O">O. Ivanova</a>, <a href="/search/astro-ph?searchtype=author&query=Krushinsky%2C+V">V. Krushinsky</a>, <a href="/search/astro-ph?searchtype=author&query=Lin%2C+Z+-">Z. -Y. Lin</a>, <a href="/search/astro-ph?searchtype=author&query=Manzini%2C+F">F. Manzini</a>, <a href="/search/astro-ph?searchtype=author&query=Maury%2C+A">A. Maury</a>, <a href="/search/astro-ph?searchtype=author&query=Moriya%2C+N">N. Moriya</a>, <a href="/search/astro-ph?searchtype=author&query=Ochner%2C+P">P. Ochner</a>, <a href="/search/astro-ph?searchtype=author&query=Oldani%2C+V">V. Oldani</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2112.10808v1-abstract-short" style="display: inline;"> There was an unprecedented opportunity to study the inner dust coma environment, where the dust and gas are not entirely decoupled, of comets 45P/Honda-Mrkos-Pajduus谩kov谩 (45P/HMP) from Dec. 26, 2016 - Mar. 15, 2017, and 46P/Wirtanen from Nov. 10, 2018 - Feb. 13, 2019, both in visible wavelengths. The radial profile slopes of these comets were measured in the R and HB-BC filters most representativ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.10808v1-abstract-full').style.display = 'inline'; document.getElementById('2112.10808v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.10808v1-abstract-full" style="display: none;"> There was an unprecedented opportunity to study the inner dust coma environment, where the dust and gas are not entirely decoupled, of comets 45P/Honda-Mrkos-Pajduus谩kov谩 (45P/HMP) from Dec. 26, 2016 - Mar. 15, 2017, and 46P/Wirtanen from Nov. 10, 2018 - Feb. 13, 2019, both in visible wavelengths. The radial profile slopes of these comets were measured in the R and HB-BC filters most representative of dust, and deviations from a radially expanding coma were identified as significant. The azimuthally averaged radial profile slope of comet 45P/HMP gradually changes from -1.81 $\pm$ 0.20 at 5.24 days pre-perihelion to -0.35 $\pm$ 0.16 at 74.41 days post perihelion. Contrastingly, the radial profile slope of 46P/Wirtanen stays fairly constant over the observed time period at -1.05 $\pm$ 0.05. Additionally, we find that the radial profile of 46P/Wirtanen is azimuthally dependent on the skyplane-projected solar position angle, while that of 45P/HMP is not. These results suggest that comet 45P/HMP and 46P/Wirtanen have vastly different coma dust environments and that their dust properties are distinct. As evident from these two comets, well-resolved inner comae are vital for detailed characterization of dust environments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.10808v1-abstract-full').style.display = 'none'; document.getElementById('2112.10808v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 pages, 13 figures, to be published in the Planetary Science Journal</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.05457">arXiv:2112.05457</a> <span> [<a href="https://arxiv.org/pdf/2112.05457">pdf</a>, <a href="https://arxiv.org/format/2112.05457">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202142438">10.1051/0004-6361/202142438 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Dynamical masses for two M1 + mid-M dwarf binaries monitored during the SPHERE-SHINE survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Biller%2C+B+A">Beth A. Biller</a>, <a href="/search/astro-ph?searchtype=author&query=Grandjean%2C+A">Antoine Grandjean</a>, <a href="/search/astro-ph?searchtype=author&query=Messina%2C+S">Sergio Messina</a>, <a href="/search/astro-ph?searchtype=author&query=Desidera%2C+S">Silvano Desidera</a>, <a href="/search/astro-ph?searchtype=author&query=Delorme%2C+P">Philippe Delorme</a>, <a href="/search/astro-ph?searchtype=author&query=Lagrange%2C+A">Anne-Marie Lagrange</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Mesa%2C+D">Dino Mesa</a>, <a href="/search/astro-ph?searchtype=author&query=Janson%2C+M">Markus Janson</a>, <a href="/search/astro-ph?searchtype=author&query=Gratton%2C+R">Raffaele Gratton</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Orazi%2C+V">Valentina D'Orazi</a>, <a href="/search/astro-ph?searchtype=author&query=Langlois%2C+M">Maud Langlois</a>, <a href="/search/astro-ph?searchtype=author&query=Maire%2C+A">Anne-Lise Maire</a>, <a href="/search/astro-ph?searchtype=author&query=Schlieder%2C+J">Joshua Schlieder</a>, <a href="/search/astro-ph?searchtype=author&query=Henning%2C+T">Thomas Henning</a>, <a href="/search/astro-ph?searchtype=author&query=Zurlo%2C+A">Alice Zurlo</a>, <a href="/search/astro-ph?searchtype=author&query=Hagelberg%2C+J">Janis Hagelberg</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+S">S. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Romero%2C+C">C. Romero</a>, <a href="/search/astro-ph?searchtype=author&query=Bonnefoy%2C+M">Micka毛l Bonnefoy</a>, <a href="/search/astro-ph?searchtype=author&query=Chauvin%2C+G">Gael Chauvin</a>, <a href="/search/astro-ph?searchtype=author&query=Feldt%2C+M">Markus Feldt</a>, <a href="/search/astro-ph?searchtype=author&query=Meyer%2C+M">Michael Meyer</a>, <a href="/search/astro-ph?searchtype=author&query=Vigan%2C+A">Arthur Vigan</a>, <a href="/search/astro-ph?searchtype=author&query=Pavlov%2C+A">A. Pavlov</a> , et al. (3 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2112.05457v1-abstract-short" style="display: inline;"> We present orbital fits and dynamical masses for HIP 113201AB and HIP 36985AB, two M1 + mid-M dwarf binary systems monitored as part of the SPHERE SHINE survey. To robustly determine ages via gyrochronology, we undertook a photometric monitoring campaign for HIP 113201 and for GJ 282AB, the two wide K star companions to HIP 36985, using the 40 cm Remote Observatory Atacama Desert (ROAD) telescope.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.05457v1-abstract-full').style.display = 'inline'; document.getElementById('2112.05457v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.05457v1-abstract-full" style="display: none;"> We present orbital fits and dynamical masses for HIP 113201AB and HIP 36985AB, two M1 + mid-M dwarf binary systems monitored as part of the SPHERE SHINE survey. To robustly determine ages via gyrochronology, we undertook a photometric monitoring campaign for HIP 113201 and for GJ 282AB, the two wide K star companions to HIP 36985, using the 40 cm Remote Observatory Atacama Desert (ROAD) telescope. We adopt ages of 1.2$\pm$0.1 Gyr for HIP 113201AB and 750$\pm$100 Myr for HIP 36985AB. To derive dynamical masses for all components of these systems, we used parallel-tempering Markov Chain Monte Carlo sampling to fit a combination of radial velocity, direct imaging, and Gaia and Hipparcos astrometry. Fitting the direct imaging and radial velocity data for HIP 113201 yields a primary mass of 0.54$\pm$0.03 M$_{\odot}$, fully consistent with its M1 spectral type, and a secondary mass of 0.145$\pm$ M$_{\odot}$. The secondary masses derived with and without including Hipparcos/Gaia data are more massive than the 0.1 M$_{\odot}$ estimated mass from the photometry of the companion. An undetected brown dwarf companion to HIP 113201B could be a natural explanation for this apparent discrepancy. At an age $>$1 Gyr, a 30 M$_{Jup}$ companion to HIP 113201B would make a negligible ($<$1$\%$) contribution to the system luminosity, but could have strong dynamical impacts. Fitting the direct imaging, radial velocity, and Hipparcos/Gaia proper motion anomaly for HIP 36985AB, we find a primary mass of 0.54$\pm$0.01 M$_{\odot}$ and a secondary mass of 0.185$\pm$0.001 M$_{\odot}$ which agree well with photometric estimates of component masses, the masses estimated from $M_{K}$-- mass relationships for M dwarf stars, and previous dynamical masses in the literature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.05457v1-abstract-full').style.display = 'none'; document.getElementById('2112.05457v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">accepted to A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 658, A145 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.01613">arXiv:2112.01613</a> <span> [<a href="https://arxiv.org/pdf/2112.01613">pdf</a>, <a href="https://arxiv.org/format/2112.01613">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics of Galaxies">astro-ph.GA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202039542">10.1051/0004-6361/202039542 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Single-lens mass measurement in the high-magnification microlensing event Gaia19bld located in the Galactic disc </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Rybicki%2C+K+A">K. A. Rybicki</a>, <a href="/search/astro-ph?searchtype=author&query=Wyrzykowski%2C+%C5%81">艁. Wyrzykowski</a>, <a href="/search/astro-ph?searchtype=author&query=Bachelet%2C+E">E. Bachelet</a>, <a href="/search/astro-ph?searchtype=author&query=Cassan%2C+A">A. Cassan</a>, <a href="/search/astro-ph?searchtype=author&query=Zieli%C5%84ski%2C+P">P. Zieli艅ski</a>, <a href="/search/astro-ph?searchtype=author&query=Gould%2C+A">A. Gould</a>, <a href="/search/astro-ph?searchtype=author&query=Novati%2C+S+C">S. Calchi Novati</a>, <a href="/search/astro-ph?searchtype=author&query=Yee%2C+J+C">J. C. Yee</a>, <a href="/search/astro-ph?searchtype=author&query=Ryu%2C+Y+-">Y. -H. Ryu</a>, <a href="/search/astro-ph?searchtype=author&query=Gromadzki%2C+M">M. Gromadzki</a>, <a href="/search/astro-ph?searchtype=author&query=Miko%C5%82ajczyk%2C+P">P. Miko艂ajczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Ihanec%2C+N">N. Ihanec</a>, <a href="/search/astro-ph?searchtype=author&query=Kruszy%C5%84ska%2C+K">K. Kruszy艅ska</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Zo%C5%82a%2C+S">S. Zo艂a</a>, <a href="/search/astro-ph?searchtype=author&query=Fossey%2C+S+J">S. J. Fossey</a>, <a href="/search/astro-ph?searchtype=author&query=Awiphan%2C+S">S. Awiphan</a>, <a href="/search/astro-ph?searchtype=author&query=Nakharutai%2C+N">N. Nakharutai</a>, <a href="/search/astro-ph?searchtype=author&query=Lewis%2C+F">F. Lewis</a>, <a href="/search/astro-ph?searchtype=author&query=E.%2C+F+O">F. Olivares E.</a>, <a href="/search/astro-ph?searchtype=author&query=Hodgkin%2C+S">S. Hodgkin</a>, <a href="/search/astro-ph?searchtype=author&query=Delgado%2C+A">A. Delgado</a>, <a href="/search/astro-ph?searchtype=author&query=Breedt%2C+E">E. Breedt</a>, <a href="/search/astro-ph?searchtype=author&query=Harrison%2C+D+L">D. L. Harrison</a>, <a href="/search/astro-ph?searchtype=author&query=vanLeeuwen%2C+M">M. vanLeeuwen</a> , et al. (44 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2112.01613v1-abstract-short" style="display: inline;"> We present the photometric analysis of Gaia19bld, a high-magnification ($A\approx60$) microlensing event located in the southern Galactic plane, which exhibited finite source and microlensing parallax effects. Due to a prompt detection by the Gaia satellite and the very high brightness of $I = 9.05~$mag at the peak, it was possible to collect a complete and unique set of multi-channel follow-up ob… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.01613v1-abstract-full').style.display = 'inline'; document.getElementById('2112.01613v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.01613v1-abstract-full" style="display: none;"> We present the photometric analysis of Gaia19bld, a high-magnification ($A\approx60$) microlensing event located in the southern Galactic plane, which exhibited finite source and microlensing parallax effects. Due to a prompt detection by the Gaia satellite and the very high brightness of $I = 9.05~$mag at the peak, it was possible to collect a complete and unique set of multi-channel follow-up observations, which allowed us to determine all parameters vital for the characterisation of the lens and the source in the microlensing event. Gaia19bld was discovered by the Gaia satellite and was subsequently intensively followed up with a network of ground-based observatories and the Spitzer Space Telescope. We collected multiple high-resolution spectra with Very Large Telescope (VLT)/X-Shooter to characterise the source star. The event was also observed with VLT Interferometer (VLTI)/PIONIER during the peak. Here we focus on the photometric observations and model the light curve composed of data from Gaia, Spitzer, and multiple optical, ground-based observatories. We find the best-fitting solution with parallax and finite source effects. We derived the limit on the luminosity of the lens based on the blended light model and spectroscopic distance. We compute the mass of the lens to be $1.13 \pm 0.03~M_{\odot}$ and derive its distance to be $5.52^{+0.35}_{-0.64}~\mathrm{kpc}$. The lens is likely a main sequence star, however its true nature has yet to be verified by future high-resolution observations. Our results are consistent with interferometric measurements of the angular Einstein radius, emphasising that interferometry can be a new channel for determining the masses of objects that would otherwise remain undetectable, including stellar-mass black holes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.01613v1-abstract-full').style.display = 'none'; document.getElementById('2112.01613v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">accepted to Astronomy&Astrophysics</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2111.12619">arXiv:2111.12619</a> <span> [<a href="https://arxiv.org/pdf/2111.12619">pdf</a>, <a href="https://arxiv.org/format/2111.12619">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stab3450">10.1093/mnras/stab3450 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A survey for variable young stars with small telescopes: V - Analysis of TXOri, V505Ori, and V510Ori, the HST ULLYSES targets in the $蟽$Ori cluster </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Froebrich%2C+D">Dirk Froebrich</a>, <a href="/search/astro-ph?searchtype=author&query=Eisl%C3%B6ffel%2C+J">Jochen Eisl枚ffel</a>, <a href="/search/astro-ph?searchtype=author&query=Stecklum%2C+B">Bringfried Stecklum</a>, <a href="/search/astro-ph?searchtype=author&query=Herbert%2C+C">Carys Herbert</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2111.12619v1-abstract-short" style="display: inline;"> Investigations of the formation of young stellar objects (YSOs) and planets require the detailed analysis of individual sources as well as statistical analysis of a larger number of objects. The Hubble UV Legacy Library of Young Stars as Essential Standards (ULLYSES) project provides such a unique opportunity by establishing a UV spectroscopic library of young high- and low-mass stars in the local… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.12619v1-abstract-full').style.display = 'inline'; document.getElementById('2111.12619v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2111.12619v1-abstract-full" style="display: none;"> Investigations of the formation of young stellar objects (YSOs) and planets require the detailed analysis of individual sources as well as statistical analysis of a larger number of objects. The Hubble UV Legacy Library of Young Stars as Essential Standards (ULLYSES) project provides such a unique opportunity by establishing a UV spectroscopic library of young high- and low-mass stars in the local universe. Here we analyse optical photometry of the three ULLYSES targets (TXOri, V505Ori, V510Ori) and other YSOs in the $蟽$Ori cluster taken at the time of the HST observations to provide a reference for those spectra. We identify three populations of YSOs along the line of sight to $蟽$Ori, separated in parallax and proper motion space. The ULLYSES targets show typical YSO behaviour with pronounced variability and mass accretion rates of the order of 10$^{-8}$M$_\odot$/yr. Optical colours do not agree with standard interstellar reddening and suggest a significant contribution of scattered light. They are also amongst the most variable and strongest accretors in the cluster. V505\,Ori shows variability with a seven day period, indicating an inner disk warp at the co-rotation radius. Uncovering the exact nature of the ULLYSES targets will require improved detailed modelling of the HST spectra in the context of the available photometry, including scattered light contributions as well as non-standard reddening. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.12619v1-abstract-full').style.display = 'none'; document.getElementById('2111.12619v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS, 17 pages, 10 figures, 5 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2110.10321">arXiv:2110.10321</a> <span> [<a href="https://arxiv.org/pdf/2110.10321">pdf</a>, <a href="https://arxiv.org/ps/2110.10321">ps</a>, <a href="https://arxiv.org/format/2110.10321">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> On the nature of embedded precursors in long outbursts of SS Cyg stars as inferred from observations of the IW And star ST Cha </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2110.10321v1-abstract-short" style="display: inline;"> We observed the IW And-type dwarf nova ST Cha and found that standstills were terminated by brightening at a constant brightness level during standstills. This finding is not consistent with a model of IW And-type dwarf novae assuming repeated enhancements of the mass-transfer rate from the secondary. We found that one outburst in ST Cha had a shoulder during the rising branch at the same level in… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.10321v1-abstract-full').style.display = 'inline'; document.getElementById('2110.10321v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.10321v1-abstract-full" style="display: none;"> We observed the IW And-type dwarf nova ST Cha and found that standstills were terminated by brightening at a constant brightness level during standstills. This finding is not consistent with a model of IW And-type dwarf novae assuming repeated enhancements of the mass-transfer rate from the secondary. We found that one outburst in ST Cha had a shoulder during the rising branch at the same level in which standstills were terminated by brightening. This phenomenon is very similar to what are called "embedded precursors" in SS Cyg stars. We propose that these embedded precursors in both SS Cyg stars and the IW And star ST Cha occur when the disk reaches the tidal truncation radius. If this is the case, precursors in SS Cyg stars and SU UMa stars are different in origin on the contrary to the idea suggested by Cannizzo (2012). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.10321v1-abstract-full').style.display = 'none'; document.getElementById('2110.10321v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 3 figures, to appear in VSOLJ Variable Star Bulletin</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.07329">arXiv:2109.07329</a> <span> [<a href="https://arxiv.org/pdf/2109.07329">pdf</a>, <a href="https://arxiv.org/format/2109.07329">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4365/ac2ee2">10.3847/1538-4365/ac2ee2 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> First results on RR Lyrae stars with the TESS space telescope: untangling the connections between mode content, colors and distances </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Moln%C3%A1r%2C+L">L谩szl贸 Moln谩r</a>, <a href="/search/astro-ph?searchtype=author&query=B%C3%B3di%2C+A">Attila B贸di</a>, <a href="/search/astro-ph?searchtype=author&query=P%C3%A1l%2C+A">Andr谩s P谩l</a>, <a href="/search/astro-ph?searchtype=author&query=Bhardwaj%2C+A">Anupam Bhardwaj</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Benk%C5%91%2C+J+M">J贸zsef M. Benk艖</a>, <a href="/search/astro-ph?searchtype=author&query=Derekas%2C+A">Aliz Derekas</a>, <a href="/search/astro-ph?searchtype=author&query=Ebadi%2C+M">Mohammad Ebadi</a>, <a href="/search/astro-ph?searchtype=author&query=Joyce%2C+M">Meridith Joyce</a>, <a href="/search/astro-ph?searchtype=author&query=Hasanzadeh%2C+A">Amir Hasanzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Kolenberg%2C+K">Katrien Kolenberg</a>, <a href="/search/astro-ph?searchtype=author&query=Lund%2C+M+B">Michael B. Lund</a>, <a href="/search/astro-ph?searchtype=author&query=Nemec%2C+J+M">James M. Nemec</a>, <a href="/search/astro-ph?searchtype=author&query=Netzel%2C+H">Henryka Netzel</a>, <a href="/search/astro-ph?searchtype=author&query=Ngeow%2C+C">Chow-Choong Ngeow</a>, <a href="/search/astro-ph?searchtype=author&query=Pepper%2C+J">Joshua Pepper</a>, <a href="/search/astro-ph?searchtype=author&query=Plachy%2C+E">Emese Plachy</a>, <a href="/search/astro-ph?searchtype=author&query=Prudil%2C+Z">Zden臎k Prudil</a>, <a href="/search/astro-ph?searchtype=author&query=Siverd%2C+R+J">Robert J. Siverd</a>, <a href="/search/astro-ph?searchtype=author&query=Skarka%2C+M">Marek Skarka</a>, <a href="/search/astro-ph?searchtype=author&query=Smolec%2C+R">Rados艂aw Smolec</a>, <a href="/search/astro-ph?searchtype=author&query=S%C3%B3dor%2C+%C3%81">脕d谩m S贸dor</a>, <a href="/search/astro-ph?searchtype=author&query=Sylla%2C+S">Salma Sylla</a>, <a href="/search/astro-ph?searchtype=author&query=Szab%C3%B3%2C+P">P谩l Szab贸</a>, <a href="/search/astro-ph?searchtype=author&query=Szab%C3%B3%2C+R">R贸bert Szab贸</a> , et al. (3 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.07329v1-abstract-short" style="display: inline;"> The TESS space telescope is collecting continuous, high-precision optical photometry of stars throughout the sky, including thousands of RR Lyrae stars. In this paper, we present results for an initial sample of 118 nearby RR Lyrae stars observed in TESS Sectors 1 and 2. We use differential-image photometry to generate light curves and analyse their mode content and modulation properties. We combi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.07329v1-abstract-full').style.display = 'inline'; document.getElementById('2109.07329v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.07329v1-abstract-full" style="display: none;"> The TESS space telescope is collecting continuous, high-precision optical photometry of stars throughout the sky, including thousands of RR Lyrae stars. In this paper, we present results for an initial sample of 118 nearby RR Lyrae stars observed in TESS Sectors 1 and 2. We use differential-image photometry to generate light curves and analyse their mode content and modulation properties. We combine accurate light curve parameters from TESS with parallax and color information from the Gaia mission to create a comprehensive classification scheme. We build a clean sample, preserving RR Lyrae stars with unusual light curve shapes, while separating other types of pulsating stars. We find that a large fraction of RR Lyrae stars exhibit various low-amplitude modes, but the distribution of those modes is markedly different from those of the bulge stars. This suggests that differences in physical parameters have an observable effect on the excitation of extra modes, potentially offering a way to uncover the origins of these signals. However, mode identification is hindered by uncertainties when identifying the true pulsation frequencies of the extra modes. We compare mode amplitude ratios in classical double-mode stars to stars with extra modes at low amplitudes and find that they separate into two distinct groups. Finally, we find a high percentage of modulated stars among the fundamental-mode pulsators, but also find that at least 28% of them do not exhibit modulation, confirming that a significant fraction of stars lack the Blazhko effect. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.07329v1-abstract-full').style.display = 'none'; document.getElementById('2109.07329v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">35 pages, 26 figures, and a 19-page appendix. Accepted for publication in ApJS. Light curve data temporarily available: https://konkoly.hu/staff/lmolnar/tess_rrl_firstlight_all_lcs.txt</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.03979">arXiv:2109.03979</a> <span> [<a href="https://arxiv.org/pdf/2109.03979">pdf</a>, <a href="https://arxiv.org/ps/2109.03979">ps</a>, <a href="https://arxiv.org/format/2109.03979">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> Orbital and spin periods of the candidate white dwarf pulsar ASASSN-V J205543.90+240033.5 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Pavlenko%2C+E+P">Elena P. Pavlenko</a>, <a href="/search/astro-ph?searchtype=author&query=Sosnovskij%2C+A+A">Aleksei A. Sosnovskij</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.03979v1-abstract-short" style="display: inline;"> ASASSN-V J205543.90+240033.5 has been suggested to be a white dwarf pulsar by Kato (2021, arXiv:2108.09060). We obtained time-resolved photometry and identified the orbital and spin periods to be 0.523490(1) d and 0.00678591(1) d = 9.77 min, respectively. These values strengthen the similarity of this object with AR Sco. We estimated that the strength of the spin pulse is 3.6 times smaller than in… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.03979v1-abstract-full').style.display = 'inline'; document.getElementById('2109.03979v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.03979v1-abstract-full" style="display: none;"> ASASSN-V J205543.90+240033.5 has been suggested to be a white dwarf pulsar by Kato (2021, arXiv:2108.09060). We obtained time-resolved photometry and identified the orbital and spin periods to be 0.523490(1) d and 0.00678591(1) d = 9.77 min, respectively. These values strengthen the similarity of this object with AR Sco. We estimated that the strength of the spin pulse is 3.6 times smaller than in AR Sco. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.03979v1-abstract-full').style.display = 'none'; document.getElementById('2109.03979v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 4 figures, to appear in VSOLJ Variable Star Bulletin</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.07868">arXiv:2108.07868</a> <span> [<a href="https://arxiv.org/pdf/2108.07868">pdf</a>, <a href="https://arxiv.org/format/2108.07868">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> The 2019 outburst of the 2005 classical nova V1047 Cen: a record breaking dwarf nova outburst or a new phenomenon? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Aydi%2C+E">E. Aydi</a>, <a href="/search/astro-ph?searchtype=author&query=Sokolovsky%2C+K+V">K. V. Sokolovsky</a>, <a href="/search/astro-ph?searchtype=author&query=Bright%2C+J+S">J. S. Bright</a>, <a href="/search/astro-ph?searchtype=author&query=Tremou%2C+E">E. Tremou</a>, <a href="/search/astro-ph?searchtype=author&query=Nyamai%2C+M+M">M. M. Nyamai</a>, <a href="/search/astro-ph?searchtype=author&query=Evans%2C+A">A. Evans</a>, <a href="/search/astro-ph?searchtype=author&query=Strader%2C+J">J. Strader</a>, <a href="/search/astro-ph?searchtype=author&query=Chomiuk%2C+L">L. Chomiuk</a>, <a href="/search/astro-ph?searchtype=author&query=Myers%2C+G">G. Myers</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">F-J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Page%2C+K+L">K. L. Page</a>, <a href="/search/astro-ph?searchtype=author&query=Buckley%2C+D+A+H">D. A. H. Buckley</a>, <a href="/search/astro-ph?searchtype=author&query=Woodward%2C+C+E">C. E. Woodward</a>, <a href="/search/astro-ph?searchtype=author&query=Walter%2C+F+M">F. M. Walter</a>, <a href="/search/astro-ph?searchtype=author&query=Mr%C3%B3z%2C+P">P. Mr贸z</a>, <a href="/search/astro-ph?searchtype=author&query=Vallely%2C+P+J">P. J. Vallely</a>, <a href="/search/astro-ph?searchtype=author&query=Geballe%2C+T+R">T. R. Geballe</a>, <a href="/search/astro-ph?searchtype=author&query=Banerjee%2C+D+P+K">D. P. K. Banerjee</a>, <a href="/search/astro-ph?searchtype=author&query=Gehrz%2C+R+D">R. D. Gehrz</a>, <a href="/search/astro-ph?searchtype=author&query=Fender%2C+R+P">R. P. Fender</a>, <a href="/search/astro-ph?searchtype=author&query=Gromadzki%2C+M">M. Gromadzki</a>, <a href="/search/astro-ph?searchtype=author&query=Kawash%2C+A">A. Kawash</a>, <a href="/search/astro-ph?searchtype=author&query=Knigge%2C+C">C. Knigge</a>, <a href="/search/astro-ph?searchtype=author&query=Mukai%2C+K">K. Mukai</a>, <a href="/search/astro-ph?searchtype=author&query=Munari%2C+U">U. Munari</a> , et al. (6 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2108.07868v2-abstract-short" style="display: inline;"> We present a detailed study of the 2019 outburst of the cataclysmic variable V1047~Cen, which hosted a classical nova eruption in 2005. The peculiar outburst occurred 14 years after the classical nova event and lasted for more than 400 days, reaching an amplitude of around 6 magnitudes in the optical. Early spectral follow-up revealed what could be a dwarf nova (accretion disk instability) outburs… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.07868v2-abstract-full').style.display = 'inline'; document.getElementById('2108.07868v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.07868v2-abstract-full" style="display: none;"> We present a detailed study of the 2019 outburst of the cataclysmic variable V1047~Cen, which hosted a classical nova eruption in 2005. The peculiar outburst occurred 14 years after the classical nova event and lasted for more than 400 days, reaching an amplitude of around 6 magnitudes in the optical. Early spectral follow-up revealed what could be a dwarf nova (accretion disk instability) outburst. However, the outburst duration, high velocity ($>$2000\,km\,s$^{-1}$) features in the optical line profiles, luminous optical emission, and presence of prominent long-lasting radio emission together suggest a phenomenon more exotic and energetic than a dwarf nova outburst. The outburst amplitude, radiated energy, and spectral evolution are also not consistent with a classical nova eruption. There are similarities between V1047~Cen's 2019 outburst and those of classical symbiotic stars, but pre-2005 images of the field of V1047~Cen indicate that the system likely hosts a dwarf companion, implying a typical cataclysmic variable system. Based on our multi-wavelength observations, we suggest that the outburst may have started with a brightening of the disk due to enhanced mass transfer or disk instability, possibly leading to enhanced nuclear shell burning on the white dwarf, which was already experiencing some level of quasi-steady shell burning. This eventually led to the generation of a wind and/or bipolar, collimated outflows. The 2019 outburst of V1047~Cen appears to be unique, and nothing similar has been observed in a typical cataclysmic variable system before, hinting at a potentially new astrophysical phenomenon. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.07868v2-abstract-full').style.display = 'none'; document.getElementById('2108.07868v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">36 pages, 24 figures, 9 tables. Accepted in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.03681">arXiv:2107.03681</a> <span> [<a href="https://arxiv.org/pdf/2107.03681">pdf</a>, <a href="https://arxiv.org/ps/2107.03681">ps</a>, <a href="https://arxiv.org/format/2107.03681">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> Optical Variability Correlated with X-ray Spectral Transition in the Black-Hole Transient ASASSN-18ey = MAXI J1820+070 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Niijima%2C+K">Keito Niijima</a>, <a href="/search/astro-ph?searchtype=author&query=Kimura%2C+M">Mariko Kimura</a>, <a href="/search/astro-ph?searchtype=author&query=Wakamatsu%2C+Y">Yasuyuki Wakamatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Nogami%2C+D">Daisaku Nogami</a>, <a href="/search/astro-ph?searchtype=author&query=Isogai%2C+K">Keisuke Isogai</a>, <a href="/search/astro-ph?searchtype=author&query=Kojiguchi%2C+N">Naoto Kojiguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Ohnishi%2C+R">Ryuhei Ohnishi</a>, <a href="/search/astro-ph?searchtype=author&query=Shidatsu%2C+M">Megumi Shidatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Stone%2C+G">Geoffrey Stone</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Tordai%2C+T">Tam谩s Tordai</a>, <a href="/search/astro-ph?searchtype=author&query=Richmond%2C+M">Michael Richmond</a>, <a href="/search/astro-ph?searchtype=author&query=Vanmunster%2C+T">Tonny Vanmunster</a>, <a href="/search/astro-ph?searchtype=author&query=Myers%2C+G">Gordon Myers</a>, <a href="/search/astro-ph?searchtype=author&query=Brincat%2C+S+M">Stephen M. Brincat</a>, <a href="/search/astro-ph?searchtype=author&query=Dubovsky%2C+P+A">Pavol A. Dubovsky</a>, <a href="/search/astro-ph?searchtype=author&query=Medulka%2C+T">Tomas Medulka</a>, <a href="/search/astro-ph?searchtype=author&query=Kudzej%2C+I">Igor Kudzej</a>, <a href="/search/astro-ph?searchtype=author&query=Parimucha%2C+S">Stefan Parimucha</a>, <a href="/search/astro-ph?searchtype=author&query=Littlefield%2C+C">Colin Littlefield</a>, <a href="/search/astro-ph?searchtype=author&query=Monard%2C+B">Berto Monard</a>, <a href="/search/astro-ph?searchtype=author&query=Ulowetz%2C+J">Joseph Ulowetz</a>, <a href="/search/astro-ph?searchtype=author&query=Pavlenko%2C+E+P">Elena P. Pavlenko</a>, <a href="/search/astro-ph?searchtype=author&query=Antonyuk%2C+O+I">Oksana I. Antonyuk</a> , et al. (27 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2107.03681v1-abstract-short" style="display: inline;"> How a black hole accretes matter and how this process is regulated are fundamental but unsolved questions in astrophysics. In transient black-hole binaries, a lot of mass stored in an accretion disk is suddenly drained to the central black hole because of thermal-viscous instability. This phenomenon is called an outburst and is observable at various wavelengths (Frank et al., 2002). During the out… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.03681v1-abstract-full').style.display = 'inline'; document.getElementById('2107.03681v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.03681v1-abstract-full" style="display: none;"> How a black hole accretes matter and how this process is regulated are fundamental but unsolved questions in astrophysics. In transient black-hole binaries, a lot of mass stored in an accretion disk is suddenly drained to the central black hole because of thermal-viscous instability. This phenomenon is called an outburst and is observable at various wavelengths (Frank et al., 2002). During the outburst, the accretion structure in the vicinity of a black hole shows dramatical transitions from a geometrically-thick hot accretion flow to a geometrically-thin disk, and the transition is observed at X-ray wavelengths (Remillard, McClintock, 2006; Done et al., 2007). However, how that X-ray transition occurs remains a major unsolved problem (Dunn et al., 2008). Here we report extensive optical photometry during the 2018 outburst of ASASSN-18ey (MAXI J1820$+$070), a black-hole binary at a distance of 3.06 kpc (Tucker et al., 2018; Torres et al., 2019) containing a black hole and a donor star of less than one solar mass. We found optical large-amplitude periodic variations similar to superhumps which are well observed in a subclass of white-dwarf binaries (Kato et al., 2009). In addition, the start of the stage transition of the optical variations was observed 5 days earlier than the X-ray transition. This is naturally explained on the basis of our knowledge regarding white dwarf binaries as follows: propagation of the eccentricity inward in the disk makes an increase of the accretion rate in the outer disk, resulting in huge mass accretion to the black hole. Moreover, we provide the dynamical estimate of the binary mass ratio by using the optical periodic variations for the first time in transient black-hole binaries. This paper opens a new window to measure black-hole masses accurately by systematic optical time-series observations which can be performed even by amateur observers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.03681v1-abstract-full').style.display = 'none'; document.getElementById('2107.03681v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">VSOLJ Variable Star Bulletin submitted</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Variable Star Bulletin, 74, 2021 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.00662">arXiv:2107.00662</a> <span> [<a href="https://arxiv.org/pdf/2107.00662">pdf</a>, <a href="https://arxiv.org/format/2107.00662">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/2515-5172/ac0c83">10.3847/2515-5172/ac0c83 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> ASASSN-21co: A detached eclipsing binary with an 11.9 year period </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Rowan%2C+D+M">D. M. Rowan</a>, <a href="/search/astro-ph?searchtype=author&query=Stanek%2C+K+Z">K. Z. Stanek</a>, <a href="/search/astro-ph?searchtype=author&query=Way%2C+Z">Z. Way</a>, <a href="/search/astro-ph?searchtype=author&query=Kochanek%2C+C+S">C. S. Kochanek</a>, <a href="/search/astro-ph?searchtype=author&query=Jayasinghe%2C+T">T. Jayasinghe</a>, <a href="/search/astro-ph?searchtype=author&query=Thompson%2C+T+A">Todd A. Thompson</a>, <a href="/search/astro-ph?searchtype=author&query=Barker%2C+H">H. Barker</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Bohlsen%2C+T">T. Bohlsen</a>, <a href="/search/astro-ph?searchtype=author&query=Kafka%2C+S">Stella Kafka</a>, <a href="/search/astro-ph?searchtype=author&query=Shappee%2C+B+J">B. J. Shappee</a>, <a href="/search/astro-ph?searchtype=author&query=Holoien%2C+T+W+-">T. W. -S. Holoien</a>, <a href="/search/astro-ph?searchtype=author&query=Prieto%2C+J+L">J. L. Prieto</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2107.00662v1-abstract-short" style="display: inline;"> We use ASAS V-band and ASAS-SN g-band observations to model the long-period detached eclipsing binary ASASSN-21co. ASAS observations show an eclipse of depth V ~ 0.6 mag in April of 2009. ASAS-SN g-band observations from March of 2021 show an eclipse of similar duration and depth, suggesting an orbital period of 11.9 years. We combine the g-band observations with additional BVRI photometry taken d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.00662v1-abstract-full').style.display = 'inline'; document.getElementById('2107.00662v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.00662v1-abstract-full" style="display: none;"> We use ASAS V-band and ASAS-SN g-band observations to model the long-period detached eclipsing binary ASASSN-21co. ASAS observations show an eclipse of depth V ~ 0.6 mag in April of 2009. ASAS-SN g-band observations from March of 2021 show an eclipse of similar duration and depth, suggesting an orbital period of 11.9 years. We combine the g-band observations with additional BVRI photometry taken during the eclipse to model the eclipse using PHOEBE. We find that the system is best described by two M giants with a ratio of secondary radius to primary radius of ~0.61. Optical spectra taken during the eclipse are consistent with at least one component of the binary being an M giant, and we find no temporal changes in the spectral features. The eclipse itself is asymmetric, showing an increase in brightness near mid-eclipse, likely due to rotational variability that is too low amplitude to be observed out-of-eclipse. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.00662v1-abstract-full').style.display = 'none'; document.getElementById('2107.00662v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 1 figure, published in RNAAS</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Res. Notes AAS 5 (2021) 147 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.15902">arXiv:2106.15902</a> <span> [<a href="https://arxiv.org/pdf/2106.15902">pdf</a>, <a href="https://arxiv.org/format/2106.15902">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202140768">10.1051/0004-6361/202140768 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A search for transiting companions in the J1407 (V1400 Cen) system </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Barmentloo%2C+S">S. Barmentloo</a>, <a href="/search/astro-ph?searchtype=author&query=Dik%2C+C">C. Dik</a>, <a href="/search/astro-ph?searchtype=author&query=Kenworthy%2C+M+A">M. A. Kenworthy</a>, <a href="/search/astro-ph?searchtype=author&query=Mamajek%2C+E+E">E. E. Mamajek</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Reichart%2C+D+E">D. E. Reichart</a>, <a href="/search/astro-ph?searchtype=author&query=Rodriguez%2C+J+E">J. E. Rodriguez</a>, <a href="/search/astro-ph?searchtype=author&query=van+Dam%2C+D+M">D. M. van Dam</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2106.15902v1-abstract-short" style="display: inline;"> In 2007, the young star 1SWASP J140747.93-394542.6 (V1400 Cen) underwent a complex series of deep eclipses over 56 days. This was attributed to the transit of a ring system filling a large fraction of the Hill sphere of an unseen substellar companion. Subsequent photometric monitoring has not found any other deep transits from this candidate ring system, but if there are more substellar companions… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.15902v1-abstract-full').style.display = 'inline'; document.getElementById('2106.15902v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.15902v1-abstract-full" style="display: none;"> In 2007, the young star 1SWASP J140747.93-394542.6 (V1400 Cen) underwent a complex series of deep eclipses over 56 days. This was attributed to the transit of a ring system filling a large fraction of the Hill sphere of an unseen substellar companion. Subsequent photometric monitoring has not found any other deep transits from this candidate ring system, but if there are more substellar companions and they are coplanar with the potential ring system, there is a chance that they will transit the star as well. This young star is active and the light curves show a 5% modulation in amplitude with a dominant rotation period of 3.2 days due to star spots rotating in and out of view. We model and remove the rotational modulation of the J1407 light curve and search for additional transit signatures of substellar companions orbiting around J1407. We combine the photometry of J1407 from several observatories, spanning a 19 year baseline. We remove the rotational modulation by modeling the variability as a periodic signal, whose periodicity changes slowly with time over several years due to the activity cycle of the star. A Transit Least Squares (TLS) analysis searches for any periodic transiting signals within the cleaned light curve. We identify an activity cycle of J1407 with a period of 5.4 years. A Transit Least Squares search does not find any plausible periodic eclipses in the light curve, from 1.2% amplitude at 5 days up to 1.9% at 20 days. This sensitivity is confirmed by injecting artificial transits into the light curve and determining the recovery fraction as a function of transit depth and orbital period. J1407 is confirmed as a young active star with an activity cycle consistent with a rapidly rotating solar mass star. With the rotational modulation removed, the TLS analysis rules out transiting companions with radii larger than about 1 Jupiter. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.15902v1-abstract-full').style.display = 'none'; document.getElementById('2106.15902v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 9 figures, 3 tables, accepted for publication in Astronomy & Astrophysics. Reduced data and reduction scripts on github at https://github.com/StanBarmentloo/J1407_transit_search_activity</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 652, A117 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.15756">arXiv:2106.15756</a> <span> [<a href="https://arxiv.org/pdf/2106.15756">pdf</a>, <a href="https://arxiv.org/ps/2106.15756">ps</a>, <a href="https://arxiv.org/format/2106.15756">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/pasj/psab073">10.1093/pasj/psab073 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the nature of the anomalous event in 2021 in the dwarf nova SS Cygni and its multi-wavelength transition </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kimura%2C+M">Mariko Kimura</a>, <a href="/search/astro-ph?searchtype=author&query=Yamada%2C+S">Shinya Yamada</a>, <a href="/search/astro-ph?searchtype=author&query=Nakaniwa%2C+N">Nozomi Nakaniwa</a>, <a href="/search/astro-ph?searchtype=author&query=Makita%2C+Y">Yoshihiro Makita</a>, <a href="/search/astro-ph?searchtype=author&query=Negoro%2C+H">Hitoshi Negoro</a>, <a href="/search/astro-ph?searchtype=author&query=Shidatsu%2C+M">Megumi Shidatsu</a>, <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Enoto%2C+T">Teruaki Enoto</a>, <a href="/search/astro-ph?searchtype=author&query=Isogai%2C+K">Keisuke Isogai</a>, <a href="/search/astro-ph?searchtype=author&query=Mihara%2C+T">Tatehiro Mihara</a>, <a href="/search/astro-ph?searchtype=author&query=Akazawa%2C+H">Hidehiko Akazawa</a>, <a href="/search/astro-ph?searchtype=author&query=Gendreau%2C+K+C">Keith C. Gendreau</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Dubovsky%2C+P+A">Pavol A. Dubovsky</a>, <a href="/search/astro-ph?searchtype=author&query=Kudzej%2C+I">Igor Kudzej</a>, <a href="/search/astro-ph?searchtype=author&query=Kasai%2C+K">Kiyoshi Kasai</a>, <a href="/search/astro-ph?searchtype=author&query=Tordai%2C+T">Tam谩s Tordai</a>, <a href="/search/astro-ph?searchtype=author&query=Pavlenko%2C+E">Elena Pavlenko</a>, <a href="/search/astro-ph?searchtype=author&query=Sosnovskij%2C+A+A">Aleksei A. Sosnovskij</a>, <a href="/search/astro-ph?searchtype=author&query=Babina%2C+J+V">Julia V. Babina</a>, <a href="/search/astro-ph?searchtype=author&query=Antonyuk%2C+O+I">Oksana I. Antonyuk</a>, <a href="/search/astro-ph?searchtype=author&query=Itoh%2C+H">Hiroshi Itoh</a>, <a href="/search/astro-ph?searchtype=author&query=Maehara%2C+H">Hiroyuki Maehara</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2106.15756v1-abstract-short" style="display: inline;"> SS Cyg has long been recognized as the prototype of a group of dwarf novae that show only outbursts. However, this object has entered a quite anomalous event in 2021, which at first appeared to be standstill, i.e., an almost constant luminosity state, observed in Z Cam-type dwarf novae. This unexpected event gives us a great opportunity to reconsider the nature of standstill in cataclysmic variabl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.15756v1-abstract-full').style.display = 'inline'; document.getElementById('2106.15756v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.15756v1-abstract-full" style="display: none;"> SS Cyg has long been recognized as the prototype of a group of dwarf novae that show only outbursts. However, this object has entered a quite anomalous event in 2021, which at first appeared to be standstill, i.e., an almost constant luminosity state, observed in Z Cam-type dwarf novae. This unexpected event gives us a great opportunity to reconsider the nature of standstill in cataclysmic variables. We have observed this anomalous event and its forerunner, a gradual and simultaneous increase in the optical and X-ray flux during quiescence, through many optical telescopes and the X-ray telescopes NICER and NuSTAR. We have not found any amplification of the orbital hump during quiescence before the anomalous event, which suggests that the mass transfer rate did not significantly fluctuate on average. The estimated X-ray flux was not enough to explain the increment of the optical flux during quiescence via X-ray irradiation of the disk and the secondary star. It would be natural to consider that viscosity in the quiescent disk was enhanced before the anomalous event, which increased mass accretion rates in the disk and raised not only the optical flux but also the X-ray flux. We suggest that enhanced viscosity also triggered the standstill-like phenomenon in SS Cyg, which is considered to be a series of small outbursts. The inner part of the disk would always stay in the outburst state and only its outer part would be unstable against the thermal-viscous instability during this phenomenon, which is consistent with the observed optical color variations. This scenario is in line with our X-ray spectral analyses which imply that the X-ray emitting inner accretion flow became hotter than usual and vertically expanded and that it became denser and was cooled down after the onset of the standstill-like state. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.15756v1-abstract-full').style.display = 'none'; document.getElementById('2106.15756v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in PASJ. 18 pages, 10 figures, and 2 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.15028">arXiv:2106.15028</a> <span> [<a href="https://arxiv.org/pdf/2106.15028">pdf</a>, <a href="https://arxiv.org/ps/2106.15028">ps</a>, <a href="https://arxiv.org/format/2106.15028">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/pasj/psab074">10.1093/pasj/psab074 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> BO Ceti: Dwarf Nova Showing Both IW And and SU UMa-Type Features </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Kato%2C+T">Taichi Kato</a>, <a href="/search/astro-ph?searchtype=author&query=Tampo%2C+Y">Yusuke Tampo</a>, <a href="/search/astro-ph?searchtype=author&query=Kojiguchi%2C+N">Naoto Kojiguchi</a>, <a href="/search/astro-ph?searchtype=author&query=Shibata%2C+M">Masaaki Shibata</a>, <a href="/search/astro-ph?searchtype=author&query=Ito%2C+J">Junpei Ito</a>, <a href="/search/astro-ph?searchtype=author&query=Isogai%2C+K">Keisuke Isogai</a>, <a href="/search/astro-ph?searchtype=author&query=Itoh%2C+H">Hiroshi Itoh</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Monard%2C+B">Berto Monard</a>, <a href="/search/astro-ph?searchtype=author&query=Kiyota%2C+S">Seiichiro Kiyota</a>, <a href="/search/astro-ph?searchtype=author&query=Vanmunster%2C+T">Tonny Vanmunster</a>, <a href="/search/astro-ph?searchtype=author&query=Sosnovskij%2C+A+A">Aleksei A. Sosnovskij</a>, <a href="/search/astro-ph?searchtype=author&query=Pavlenko%2C+E+P">Elena P. Pavlenko</a>, <a href="/search/astro-ph?searchtype=author&query=Dubovsky%2C+P+A">Pavol A. Dubovsky</a>, <a href="/search/astro-ph?searchtype=author&query=Kudzej%2C+I">Igor Kudzej</a>, <a href="/search/astro-ph?searchtype=author&query=Medulka%2C+T">Tomas Medulka</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2106.15028v1-abstract-short" style="display: inline;"> IW And stars are a recently recognized subgroup of dwarf novae which are characterized by (often repetitive) slowly rising standstills terminated by brightening, but the exact mechanism for this variation is not yet identified. We have identified BO Cet, which had been considered as a novalike cataclysmic variable, as a new member of IW And stars based on the behavior in 2019-2020. In addition to… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.15028v1-abstract-full').style.display = 'inline'; document.getElementById('2106.15028v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.15028v1-abstract-full" style="display: none;"> IW And stars are a recently recognized subgroup of dwarf novae which are characterized by (often repetitive) slowly rising standstills terminated by brightening, but the exact mechanism for this variation is not yet identified. We have identified BO Cet, which had been considered as a novalike cataclysmic variable, as a new member of IW And stars based on the behavior in 2019-2020. In addition to this, the object showed dwarf nova-type outbursts in 2020-2021, and superhumps having a period 7.8% longer than the orbital one developed at least during one long outburst. This object has been confirmed as an SU UMa-type dwarf nova with an exceptionally long orbital period (0.1398 d). BO Cet is thus the first cataclysmic variable showing both SU UMa-type and IW And-type features. We obtained a mass ratio (q) of 0.31-0.34 from the superhumps in the growing phase (stage A superhumps). At this q, the radius of the 3:1 resonance, responsible for tidal instability and superhumps, and the tidal truncation radius are very similar. We interpret that in some occasions this object showed IW And-type variation when the disk size was not large enough, but that the radius of the 3:1 resonance could be reached as the result of thermal instability. We also discuss that there are SU UMa-type dwarf novae above q=0.30, which is above the previously considered limit (q~0.25) derived from numerical simulations and that this is possible since the radius of the 3:1 resonance is inside the tidal truncation radius. We constrained the mass of the white dwarf larger than 1.0Msol, which may be responsible for the IW And-type behavior and the observed strength of the He II emission. The exact reason, however, why this object is unique in that it shows both SU UMa-type and IW And-type features is still unsolved. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.15028v1-abstract-full').style.display = 'none'; document.getElementById('2106.15028v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 7 figures, supporting information (sibo.pdf), accepted for publication in PASJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.02686">arXiv:2104.02686</a> <span> [<a href="https://arxiv.org/pdf/2104.02686">pdf</a>, <a href="https://arxiv.org/ps/2104.02686">ps</a>, <a href="https://arxiv.org/format/2104.02686">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stab1620">10.1093/mnras/stab1620 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The GALAH Survey and Symbiotic Stars. I. Discovery and follow-up of 33 candidate accreting-only systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Munari%2C+U">U. Munari</a>, <a href="/search/astro-ph?searchtype=author&query=Traven%2C+G">G. Traven</a>, <a href="/search/astro-ph?searchtype=author&query=Masetti%2C+N">N. Masetti</a>, <a href="/search/astro-ph?searchtype=author&query=Valisa%2C+P">P. Valisa</a>, <a href="/search/astro-ph?searchtype=author&query=Righetti%2C+G+-">G. -L. Righetti</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Frigo%2C+A">A. Frigo</a>, <a href="/search/astro-ph?searchtype=author&query=Cotar%2C+K">K. Cotar</a>, <a href="/search/astro-ph?searchtype=author&query=De+Silva%2C+G+M">G. M. De Silva</a>, <a href="/search/astro-ph?searchtype=author&query=Freeman%2C+K+C">K. C. Freeman</a>, <a href="/search/astro-ph?searchtype=author&query=Lewis%2C+G+F">G. F. Lewis</a>, <a href="/search/astro-ph?searchtype=author&query=Martell%2C+S+L">S. L. Martell</a>, <a href="/search/astro-ph?searchtype=author&query=Sharma%2C+S">S. Sharma</a>, <a href="/search/astro-ph?searchtype=author&query=Simpson%2C+J+D">J. D. Simpson</a>, <a href="/search/astro-ph?searchtype=author&query=Ting%2C+Y+-">Y. -S. Ting</a>, <a href="/search/astro-ph?searchtype=author&query=Wittenmyer%2C+R+A">R. A. Wittenmyer</a>, <a href="/search/astro-ph?searchtype=author&query=Zucker%2C+D+B">D. B. Zucker</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2104.02686v1-abstract-short" style="display: inline;"> We have identified a first group of 33 new candidates for symbiotic stars (SySt) of the accreting-only variety among the 600,255 stars so far observed by the GALAH high-resolution spectroscopic survey of the Southern Hemisphere, more than doubling the number of those previously known. GALAH aims to high latitudes and this offers the possibility to sound the Galaxy for new SySt away from the usual… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.02686v1-abstract-full').style.display = 'inline'; document.getElementById('2104.02686v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.02686v1-abstract-full" style="display: none;"> We have identified a first group of 33 new candidates for symbiotic stars (SySt) of the accreting-only variety among the 600,255 stars so far observed by the GALAH high-resolution spectroscopic survey of the Southern Hemisphere, more than doubling the number of those previously known. GALAH aims to high latitudes and this offers the possibility to sound the Galaxy for new SySt away from the usual Plane and Bulge hunting regions. In this paper we focus on SySt of the M spectral type, showing an Halpha emission with a peak in excess of 0.5 above the adjacent continuum level, and not affected by coherent radial pulsations. These constraints will be relaxed in future studies. The 33 new candidate SySt were subjected to a vast array of follow-up confirmatory observations (X-ray/UV observations with the Swift satellite, search for optical flickering, presence of a near-UV upturn in ground-based photometric and spectroscopic data, radial velocity changes suggestive of orbital motion, variability of the emission line profiles). According to Gaia eDR3 parallaxes, the new SySt are located at the tip of the Giant Branch, sharing the same distribution in M(Ks) of the well established SySt. The accretion luminosities of the new SySt are in the range 1-10 Lsun, corresponding to mass-accretion rates of 0.1-1x10(-9) Msun/yr for WDs of 1 Msun. The M giant of one of the new SySt presents a large Lithium over-abundance. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.02686v1-abstract-full').style.display = 'none'; document.getElementById('2104.02686v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">MNRAS, revised version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.04366">arXiv:2103.04366</a> <span> [<a href="https://arxiv.org/pdf/2103.04366">pdf</a>, <a href="https://arxiv.org/format/2103.04366">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202038806">10.1051/0004-6361/202038806 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The SPHERE infrared survey for exoplanets (SHINE)- I Sample definition and target characterization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Desidera%2C+S">S. Desidera</a>, <a href="/search/astro-ph?searchtype=author&query=Chauvin%2C+G">G. Chauvin</a>, <a href="/search/astro-ph?searchtype=author&query=Bonavita%2C+M">M. Bonavita</a>, <a href="/search/astro-ph?searchtype=author&query=Messina%2C+S">S. Messina</a>, <a href="/search/astro-ph?searchtype=author&query=LeCoroller%2C+H">H. LeCoroller</a>, <a href="/search/astro-ph?searchtype=author&query=Schmidt%2C+T">T. Schmidt</a>, <a href="/search/astro-ph?searchtype=author&query=Gratton%2C+R">R. Gratton</a>, <a href="/search/astro-ph?searchtype=author&query=Lazzoni%2C+C">C. Lazzoni</a>, <a href="/search/astro-ph?searchtype=author&query=Meyer%2C+M">M. Meyer</a>, <a href="/search/astro-ph?searchtype=author&query=Schlieder%2C+J">J. Schlieder</a>, <a href="/search/astro-ph?searchtype=author&query=Cheetham%2C+A">A. Cheetham</a>, <a href="/search/astro-ph?searchtype=author&query=Hagelberg%2C+J">J. Hagelberg</a>, <a href="/search/astro-ph?searchtype=author&query=Bonnefoy%2C+M">M. Bonnefoy</a>, <a href="/search/astro-ph?searchtype=author&query=Feldt%2C+M">M. Feldt</a>, <a href="/search/astro-ph?searchtype=author&query=Lagrange%2C+A">A-M. Lagrange</a>, <a href="/search/astro-ph?searchtype=author&query=Langlois%2C+M">M. Langlois</a>, <a href="/search/astro-ph?searchtype=author&query=Vigan%2C+A">A. Vigan</a>, <a href="/search/astro-ph?searchtype=author&query=Tan%2C+T+G">T. G. Tan</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Millward%2C+M">M. Millward</a>, <a href="/search/astro-ph?searchtype=author&query=Alcala%2C+J">J. Alcala</a>, <a href="/search/astro-ph?searchtype=author&query=Benatti%2C+S">S. Benatti</a>, <a href="/search/astro-ph?searchtype=author&query=Brandner%2C+W">W. Brandner</a>, <a href="/search/astro-ph?searchtype=author&query=Carson%2C+J">J. Carson</a>, <a href="/search/astro-ph?searchtype=author&query=Covino%2C+E">E. Covino</a> , et al. (83 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2103.04366v1-abstract-short" style="display: inline;"> Large surveys with new-generation high-contrast imaging instruments are needed to derive the frequency and properties of exoplanet populations with separations from $\sim$5 to 300 AU. A careful assessment of the stellar properties is crucial for a proper understanding of when, where, and how frequently planets form, and how they evolve. The sensitivity of detection limits to stellar age makes this… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.04366v1-abstract-full').style.display = 'inline'; document.getElementById('2103.04366v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.04366v1-abstract-full" style="display: none;"> Large surveys with new-generation high-contrast imaging instruments are needed to derive the frequency and properties of exoplanet populations with separations from $\sim$5 to 300 AU. A careful assessment of the stellar properties is crucial for a proper understanding of when, where, and how frequently planets form, and how they evolve. The sensitivity of detection limits to stellar age makes this a key parameter for direct imaging surveys. We describe the SpHere INfrared survey for Exoplanets (SHINE), the largest direct imaging planet-search campaign initiated at the VLT in 2015 in the context of the SPHERE Guaranteed Time Observations of the SPHERE consortium. In this first paper we present the selection and the properties of the complete sample of stars surveyed with SHINE, focusing on the targets observed during the first phase of the survey (from February 2015 to February 2017). This early sample composed of 150 stars is used to perform a preliminary statistical analysis of the SHINE data, deferred to two companion papers presenting the survey performance, main discoveries, and the preliminary statistical constraints set by SHINE. Based on a large database collecting the stellar properties of all young nearby stars in the solar vicinity (including kinematics, membership to moving groups, isochrones, lithium abundance, rotation, and activity), we selected the original sample of 800 stars that were ranked in order of priority according to their sensitivity for planet detection in direct imaging with SPHERE. The properties of the stars that are part of the early statistical sample were revisited, including for instance measurements from the GAIA Data Release 2. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.04366v1-abstract-full').style.display = 'none'; document.getElementById('2103.04366v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 651, A70 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2102.09748">arXiv:2102.09748</a> <span> [<a href="https://arxiv.org/pdf/2102.09748">pdf</a>, <a href="https://arxiv.org/ps/2102.09748">ps</a>, <a href="https://arxiv.org/format/2102.09748">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/abe871">10.3847/1538-4357/abe871 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> HO Puppis: Not a Be Star but a Newly Confirmed IW And-Type Star </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Lee%2C+C">Chien-De Lee</a>, <a href="/search/astro-ph?searchtype=author&query=Ou%2C+J">Jia-Yu Ou</a>, <a href="/search/astro-ph?searchtype=author&query=Yu%2C+P">Po-Chieh Yu</a>, <a href="/search/astro-ph?searchtype=author&query=Ngeow%2C+C">Chow-Choong Ngeow</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+P">Po-Chieh Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Ip%2C+W">Wing-Huen Ip</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Sung%2C+H">Hyun-il Sung</a>, <a href="/search/astro-ph?searchtype=author&query=van+Roestel%2C+J">Jan van Roestel</a>, <a href="/search/astro-ph?searchtype=author&query=Dekany%2C+R">Richard Dekany</a>, <a href="/search/astro-ph?searchtype=author&query=Drake%2C+A+J">Andrew J. Drake</a>, <a href="/search/astro-ph?searchtype=author&query=Graham%2C+M+J">Matthew J. Graham</a>, <a href="/search/astro-ph?searchtype=author&query=Duev%2C+D+A">Dmitry A. Duev</a>, <a href="/search/astro-ph?searchtype=author&query=Kaye%2C+S">Stephen Kaye</a>, <a href="/search/astro-ph?searchtype=author&query=Kupfer%2C+T">Thomas Kupfer</a>, <a href="/search/astro-ph?searchtype=author&query=Laher%2C+R+R">Russ R. Laher</a>, <a href="/search/astro-ph?searchtype=author&query=Masci%2C+F+J">Frank J. Masci</a>, <a href="/search/astro-ph?searchtype=author&query=Mroz%2C+P">Przemek Mroz</a>, <a href="/search/astro-ph?searchtype=author&query=Neill%2C+J+D">James D. Neill</a>, <a href="/search/astro-ph?searchtype=author&query=Riddle%2C+R">Reed Riddle</a>, <a href="/search/astro-ph?searchtype=author&query=Rusholme%2C+B">Ben Rusholme</a>, <a href="/search/astro-ph?searchtype=author&query=Walters%2C+R">Richard Walters</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2102.09748v1-abstract-short" style="display: inline;"> HO Puppis (HO Pup) was considered as a Be-star candidate based on its gamma-Cassiopeiae-type light curve, but lacked spectroscopic confirmation. Using distance measured from Gaia Data Release 2 and the spectral-energy-distribution (SED) fit on broadband photometry, the Be-star nature of HO Pup is ruled out. Furthermore, based on the 28,700 photometric data points collected from various time-domain… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.09748v1-abstract-full').style.display = 'inline'; document.getElementById('2102.09748v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2102.09748v1-abstract-full" style="display: none;"> HO Puppis (HO Pup) was considered as a Be-star candidate based on its gamma-Cassiopeiae-type light curve, but lacked spectroscopic confirmation. Using distance measured from Gaia Data Release 2 and the spectral-energy-distribution (SED) fit on broadband photometry, the Be-star nature of HO Pup is ruled out. Furthermore, based on the 28,700 photometric data points collected from various time-domain surveys and dedicated intensive-monitoring observations, the light curves of HO Pup closely resemble IW And-type stars (as pointed out in Kimura et al. 2020a), exhibiting characteristics such as quasi-standstill phase, brightening, and dips. The light curve of HO Pup displays various variability timescales, including brightening cycles ranging from 23 to 61 days, variations with periods between 3.9 days and 50 minutes during the quasi-standstill phase, and a semi-regular ~14-day period for the dip events. We have also collected time-series spectra (with various spectral resolutions), in which Balmer emission lines and other expected spectral lines for an IW And-type star were detected (even though some of these lines were also expected to be present for Be stars). We detect Bowen fluorescence near the brightening phase, and that can be used to discriminate between IW And-type stars and Be stars. Finally, despite only observing for four nights, the polarization variation was detected, indicating that HO Pup has significant intrinsic polarization. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.09748v1-abstract-full').style.display = 'none'; document.getElementById('2102.09748v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 February, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">24 pages, 7 tables and 12 figures; ApJ accepted</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.02212">arXiv:2101.02212</a> <span> [<a href="https://arxiv.org/pdf/2101.02212">pdf</a>, <a href="https://arxiv.org/format/2101.02212">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stab907">10.1093/mnras/stab907 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Unicorn in Monoceros: the $3M_\odot$ dark companion to the bright, nearby red giant V723 Mon is a non-interacting, mass-gap black hole candidate </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jayasinghe%2C+T">T. Jayasinghe</a>, <a href="/search/astro-ph?searchtype=author&query=Stanek%2C+K+Z">K. Z. Stanek</a>, <a href="/search/astro-ph?searchtype=author&query=Thompson%2C+T+A">Todd A. Thompson</a>, <a href="/search/astro-ph?searchtype=author&query=Kochanek%2C+C+S">C. S. Kochanek</a>, <a href="/search/astro-ph?searchtype=author&query=Rowan%2C+D+M">D. M. Rowan</a>, <a href="/search/astro-ph?searchtype=author&query=Vallely%2C+P+J">P. J. Vallely</a>, <a href="/search/astro-ph?searchtype=author&query=Strassmeier%2C+K+G">K. G. Strassmeier</a>, <a href="/search/astro-ph?searchtype=author&query=Weber%2C+M">M. Weber</a>, <a href="/search/astro-ph?searchtype=author&query=Hinkle%2C+J+T">J. T. Hinkle</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Martin%2C+D">D. Martin</a>, <a href="/search/astro-ph?searchtype=author&query=Prieto%2C+J+L">J. L. Prieto</a>, <a href="/search/astro-ph?searchtype=author&query=Pessi%2C+T">T. Pessi</a>, <a href="/search/astro-ph?searchtype=author&query=Huber%2C+D">D. Huber</a>, <a href="/search/astro-ph?searchtype=author&query=Auchettl%2C+K">K. Auchettl</a>, <a href="/search/astro-ph?searchtype=author&query=Lopez%2C+L+A">L. A. Lopez</a>, <a href="/search/astro-ph?searchtype=author&query=Ilyin%2C+I">I. Ilyin</a>, <a href="/search/astro-ph?searchtype=author&query=Badenes%2C+C">C. Badenes</a>, <a href="/search/astro-ph?searchtype=author&query=Howard%2C+A+W">A. W. Howard</a>, <a href="/search/astro-ph?searchtype=author&query=Isaacson%2C+H">H. Isaacson</a>, <a href="/search/astro-ph?searchtype=author&query=Murphy%2C+S+J">S. J. Murphy</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.02212v2-abstract-short" style="display: inline;"> We report the discovery of the closest known black hole candidate as a binary companion to V723 Mon. V723 Mon is a nearby ($d\sim460\,\rm pc$), bright ($V\simeq8.3$~mag), evolved ($T_{\rm eff, giant}\simeq4440$~K, and $L_{\rm giant}\simeq173~L_\odot$) red giant in a high mass function, $f(M)=1.72\pm 0.01~M_\odot$, nearly circular binary ($P=59.9$ d, $e\simeq 0$). V723 Mon is a known variable star,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.02212v2-abstract-full').style.display = 'inline'; document.getElementById('2101.02212v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.02212v2-abstract-full" style="display: none;"> We report the discovery of the closest known black hole candidate as a binary companion to V723 Mon. V723 Mon is a nearby ($d\sim460\,\rm pc$), bright ($V\simeq8.3$~mag), evolved ($T_{\rm eff, giant}\simeq4440$~K, and $L_{\rm giant}\simeq173~L_\odot$) red giant in a high mass function, $f(M)=1.72\pm 0.01~M_\odot$, nearly circular binary ($P=59.9$ d, $e\simeq 0$). V723 Mon is a known variable star, previously classified as an eclipsing binary, but its All-Sky Automated Survey (ASAS), Kilodegree Extremely Little Telescope (KELT), and Transiting Exoplanet Survey Satellite (TESS) light curves are those of a nearly edge-on ellipsoidal variable. Detailed models of the light curves constrained by the period, radial velocities and stellar temperature give an inclination of $87.0^\circ{}^{+1.7^{\circ}}_{-1.4^{\circ}} $, a mass ratio of $q\simeq0.33\pm0.02$, a companion mass of $M_{\rm comp}=3.04\pm0.06~M_\odot$, a stellar radius of $R_{\rm giant}=24.9\pm0.7~R_\odot$, and a giant mass of $M_{\rm giant}=1.00\pm0.07~ M_\odot$. We identify a likely non-stellar, diffuse veiling component with contributions in the $B$ and $V$-band of ${\sim}63\%$ and ${\sim}24\%$, respectively. The SED and the absence of continuum eclipses imply that the companion mass must be dominated by a compact object. We do observe eclipses of the Balmer lines when the dark companion passes behind the giant, but their velocity spreads are low compared to observed accretion disks. The X-ray luminosity of the system is $L_{\rm X}\simeq7.6\times10^{29}~\rm ergs~s^{-1}$, corresponding to $L/L_{\rm edd}{\sim}10^{-9}$. The simplest explanation for the massive companion is a single compact object, most likely a black hole in the "mass gap". <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.02212v2-abstract-full').style.display = 'none'; document.getElementById('2101.02212v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">28 pages, 16 figures. Accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.11511">arXiv:2012.11511</a> <span> [<a href="https://arxiv.org/pdf/2012.11511">pdf</a>, <a href="https://arxiv.org/ps/2012.11511">ps</a>, <a href="https://arxiv.org/format/2012.11511">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.31577/caosp.2021.51.2.103">10.31577/caosp.2021.51.2.103 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Photometry and spectroscopy of the new symbiotic star 2SXPS J173508.4-292958 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Munari%2C+U">U. Munari</a>, <a href="/search/astro-ph?searchtype=author&query=Valisa%2C+P">P. Valisa</a>, <a href="/search/astro-ph?searchtype=author&query=Vagnozzi%2C+A">A. Vagnozzi</a>, <a href="/search/astro-ph?searchtype=author&query=Dallaporta%2C+S">S. Dallaporta</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+J">F. J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Frigo%2C+A">A. Frigo</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2012.11511v1-abstract-short" style="display: inline;"> We present and discuss the results of our photometric and spectroscopic monitoring of 2SXPS J173508.4-292958 carried out from April to August 2020. This X-ray source, in the foreground with respect to the Galactic center, brightened in X-rays during 2020, prompting our follow-up optical observations. We found the star to contain a K4III giant with a modest but highly variable Halpha emission, comp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.11511v1-abstract-full').style.display = 'inline'; document.getElementById('2012.11511v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.11511v1-abstract-full" style="display: none;"> We present and discuss the results of our photometric and spectroscopic monitoring of 2SXPS J173508.4-292958 carried out from April to August 2020. This X-ray source, in the foreground with respect to the Galactic center, brightened in X-rays during 2020, prompting our follow-up optical observations. We found the star to contain a K4III giant with a modest but highly variable Halpha emission, composed by a ~470 km/s wide component with superimposed a narrow absorption, offset by a positive velocity with respect to the giant. No orbital motion is detected for the K4III, showing an heliocentric radial velocity stable at -12(+/-1) km/s. No flickering in excess of 0.005 mag in B band was observed at three separate visits of 2SXPS J173508.4-292958. While photometrically stable in 2016 through 2018, in 2019 the star developed a limited photometric variability, that in 2020 took the form of a sinusoidal modulation with a period of 38 days and an amplitude of 0.12 mag in V band. We argue this variability cannot be ascribed to Roche-lobe filling by the K4III star. No correlation is observed between the photometric variability and the amount of emission in Halpha, the latter probably originating directly from the accretion disk around the accreting companion. While no emission from dust is detected at mid-IR wavelengths, an excess in U-band is probably present and caused by direct emission from the accretion disk. We conclude that 2SXPS J173508.4-292958 is a new symbiotic star of the accreting-only variety (AO-SySt). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.11511v1-abstract-full').style.display = 'none'; document.getElementById('2012.11511v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">accepted in press in CAOSP (15 pages, 7 figures)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.09709">arXiv:2012.09709</a> <span> [<a href="https://arxiv.org/pdf/2012.09709">pdf</a>, <a href="https://arxiv.org/format/2012.09709">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4365/abd4e3">10.3847/1538-4365/abd4e3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> TESS observations of Cepheid stars: first light results </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Plachy%2C+E">E. Plachy</a>, <a href="/search/astro-ph?searchtype=author&query=P%C3%A1l%2C+A">A. P谩l</a>, <a href="/search/astro-ph?searchtype=author&query=B%C3%B3di%2C+A">A. B贸di</a>, <a href="/search/astro-ph?searchtype=author&query=Szab%C3%B3%2C+P">P. Szab贸</a>, <a href="/search/astro-ph?searchtype=author&query=Moln%C3%A1r%2C+L">L. Moln谩r</a>, <a href="/search/astro-ph?searchtype=author&query=Szabados%2C+L">L. Szabados</a>, <a href="/search/astro-ph?searchtype=author&query=Benk%C5%91%2C+J+M">J. M. Benk艖</a>, <a href="/search/astro-ph?searchtype=author&query=Anderson%2C+R+I">R. I. Anderson</a>, <a href="/search/astro-ph?searchtype=author&query=Bellinger%2C+E+P">E. P. Bellinger</a>, <a href="/search/astro-ph?searchtype=author&query=Bhardwaj%2C+A">A. Bhardwaj</a>, <a href="/search/astro-ph?searchtype=author&query=Ebadi%2C+M">M. Ebadi</a>, <a href="/search/astro-ph?searchtype=author&query=Gazeas%2C+K">K. Gazeas</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Hasanzadeh%2C+A">A. Hasanzadeh</a>, <a href="/search/astro-ph?searchtype=author&query=Jurkovic%2C+M+I">M. I. Jurkovic</a>, <a href="/search/astro-ph?searchtype=author&query=Kalaee%2C+M+J">M. J. Kalaee</a>, <a href="/search/astro-ph?searchtype=author&query=Kervella%2C+P">P. Kervella</a>, <a href="/search/astro-ph?searchtype=author&query=Kolenberg%2C+K">K. Kolenberg</a>, <a href="/search/astro-ph?searchtype=author&query=Miko%C5%82ajczyk%2C+P">P. Miko艂ajczyk</a>, <a href="/search/astro-ph?searchtype=author&query=Nardetto%2C+N">N. Nardetto</a>, <a href="/search/astro-ph?searchtype=author&query=Nemec%2C+J+M">J. M. Nemec</a>, <a href="/search/astro-ph?searchtype=author&query=Netzel%2C+H">H. Netzel</a>, <a href="/search/astro-ph?searchtype=author&query=Ngeow%2C+C+-">C. -C. Ngeow</a>, <a href="/search/astro-ph?searchtype=author&query=Ozuyar%2C+D">D. Ozuyar</a>, <a href="/search/astro-ph?searchtype=author&query=Pascual-Granado%2C+J">J. Pascual-Granado</a> , et al. (11 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2012.09709v1-abstract-short" style="display: inline;"> We present the first analysis of Cepheid stars observed by the TESS space mission in Sectors 1 to 5. Our sample consists of 25 pulsators: ten fundamental mode, three overtone and two double-mode classical Cepheids, plus three Type II and seven anomalous Cepheids. The targets were chosen from fields with different stellar densities, both from the Galactic field and from the Magellanic System. Three… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.09709v1-abstract-full').style.display = 'inline'; document.getElementById('2012.09709v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.09709v1-abstract-full" style="display: none;"> We present the first analysis of Cepheid stars observed by the TESS space mission in Sectors 1 to 5. Our sample consists of 25 pulsators: ten fundamental mode, three overtone and two double-mode classical Cepheids, plus three Type II and seven anomalous Cepheids. The targets were chosen from fields with different stellar densities, both from the Galactic field and from the Magellanic System. Three targets have 2-minute cadence light curves available by the TESS Science Processing Operations Center: for the rest, we prepared custom light curves from the full-frame images with our own differential photometric FITSH pipeline. Our main goal was to explore the potential and the limitations of TESS concerning the various subtypes of Cepheids. We detected many low amplitude features: weak modulation, period jitter, and timing variations due to light-time effect. We also report signs of non-radial modes and the first discovery of such a mode in an anomalous Cepheid, the overtone star XZ Cet, which we then confirmed with ground-based multicolor photometric measurements. We prepared a custom photometric solution to minimize saturation effects in the bright fundamental-mode classical Cepheid, $尾$ Dor with the lightkurve software, and we revealed strong evidence of cycle-to-cycle variations in the star. In several cases, however, fluctuations in the pulsation could not be distinguished from instrumental effects, such as contamination from nearby sources which also varies between sectors. Finally, we discuss how precise light curve shapes will be crucial not only for classification purposes but also to determine physical properties of these stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.09709v1-abstract-full').style.display = 'none'; document.getElementById('2012.09709v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">30 pages, 18 figures, accepted for publication in ApJS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.08271">arXiv:2012.08271</a> <span> [<a href="https://arxiv.org/pdf/2012.08271">pdf</a>, <a href="https://arxiv.org/format/2012.08271">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> </div> <p class="title is-5 mathjax"> AR Ser: photometric observations of a Blazhko star </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bonnardeau%2C+M">Michel Bonnardeau</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2012.08271v1-abstract-short" style="display: inline;"> Photometric observations in 2010-2014 of the RR Lyrae star AR Serpentis are presented and analyzed. Two Blazhko modulations of comparable amplitude are detected, with the periods 89 and 108 days, and with evidence for irregularities. </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.08271v1-abstract-full" style="display: none;"> Photometric observations in 2010-2014 of the RR Lyrae star AR Serpentis are presented and analyzed. Two Blazhko modulations of comparable amplitude are detected, with the periods 89 and 108 days, and with evidence for irregularities. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.08271v1-abstract-full').style.display = 'none'; document.getElementById('2012.08271v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> IBVS (2015) 6132 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2010.11199">arXiv:2010.11199</a> <span> [<a href="https://arxiv.org/pdf/2010.11199">pdf</a>, <a href="https://arxiv.org/format/2010.11199">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-3881/abc259">10.3847/1538-3881/abc259 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An Asymmetric Eclipse Seen Towards the Pre-Main Sequence Binary System V928 Tau </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=van+Dam%2C+D">Dirk van Dam</a>, <a href="/search/astro-ph?searchtype=author&query=Kenworthy%2C+M">Matthew Kenworthy</a>, <a href="/search/astro-ph?searchtype=author&query=David%2C+T">Trevor David</a>, <a href="/search/astro-ph?searchtype=author&query=Mamajek%2C+E">Eric Mamajek</a>, <a href="/search/astro-ph?searchtype=author&query=Hillenbrand%2C+L">Lynne Hillenbrand</a>, <a href="/search/astro-ph?searchtype=author&query=Cody%2C+A+M">Anne Marie Cody</a>, <a href="/search/astro-ph?searchtype=author&query=Howard%2C+A">Andrew Howard</a>, <a href="/search/astro-ph?searchtype=author&query=Isaacson%2C+H">Howard Isaacson</a>, <a href="/search/astro-ph?searchtype=author&query=Ciardi%2C+D">David Ciardi</a>, <a href="/search/astro-ph?searchtype=author&query=Rebull%2C+L">Luisa Rebull</a>, <a href="/search/astro-ph?searchtype=author&query=Stauffer%2C+J">John Stauffer</a>, <a href="/search/astro-ph?searchtype=author&query=Patel%2C+R">Rahul Patel</a>, <a href="/search/astro-ph?searchtype=author&query=Cameron%2C+A+C">Andrew Collier Cameron</a>, <a href="/search/astro-ph?searchtype=author&query=Rodriguez%2C+J">Joseph Rodriguez</a>, <a href="/search/astro-ph?searchtype=author&query=Pojma%C5%84ski%2C+G">Grzegorz Pojma艅ski</a>, <a href="/search/astro-ph?searchtype=author&query=Gonzales%2C+E">Erica Gonzales</a>, <a href="/search/astro-ph?searchtype=author&query=Schlieder%2C+J">Joshua Schlieder</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Dufoer%2C+S">Sjoerd Dufoer</a>, <a href="/search/astro-ph?searchtype=author&query=Vanmunster%2C+T">Tonny Vanmunster</a>, <a href="/search/astro-ph?searchtype=author&query=Dubois%2C+F">Franky Dubois</a>, <a href="/search/astro-ph?searchtype=author&query=Vanaverbeke%2C+S">Siegfried Vanaverbeke</a>, <a href="/search/astro-ph?searchtype=author&query=Logie%2C+L">Ludwig Logie</a>, <a href="/search/astro-ph?searchtype=author&query=Rau%2C+S">Steve Rau</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2010.11199v1-abstract-short" style="display: inline;"> K2 observations of the weak-lined T Tauri binary V928 Tau A+B show the detection of a single, asymmetric eclipse which may be due to a previously unknown substellar companion eclipsing one component of the binary with an orbital period $>$ 66 days. Over an interval of about 9 hours, one component of the binary dims by around 60%, returning to its normal brightness about 5 hours later. From modelin… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.11199v1-abstract-full').style.display = 'inline'; document.getElementById('2010.11199v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.11199v1-abstract-full" style="display: none;"> K2 observations of the weak-lined T Tauri binary V928 Tau A+B show the detection of a single, asymmetric eclipse which may be due to a previously unknown substellar companion eclipsing one component of the binary with an orbital period $>$ 66 days. Over an interval of about 9 hours, one component of the binary dims by around 60%, returning to its normal brightness about 5 hours later. From modeling of the eclipse shape we find evidence that the eclipsing companion may be surrounded by a disk or a vast ring system. The modeled disk has a radius of $0.9923\,\pm\,0.0005\,R_*$, with an inclination of $56.78\,\pm\, 0.03^\circ$, a tilt of $41.22\,\pm\,0.05^\circ$, an impact parameter of $-0.2506\,\pm\,0.0002\,R_*$ and an opacity of 1.00. The occulting disk must also move at a transverse velocity of $6.637\,\pm\,0.002\,R_*\,\mathrm{day}^{-1}$, which depending on whether it orbits V928 Tau A or B, corresponds to approximately 73.53 or 69.26 $\mathrm{km s}^{-1}$. A search in ground based archival data reveals additional dimming events, some of which suggest periodicity, but no unambiguous period associated with the eclipse observed by K2. We present a new epoch of astrometry which is used to further refine the orbit of the binary, presenting a new lower bound of 67 years, and constraints on the possible orbital periods of the eclipsing companion. The binary is also separated by 18" ($\sim$2250 au) from the lower mass CFHT-BD-Tau 7, which is likely associated with V928 Tau A+B. We also present new high dispersion optical spectroscopy that we use to characterize the unresolved stellar binary. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.11199v1-abstract-full').style.display = 'none'; document.getElementById('2010.11199v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">30 pages, 9 tables, 10 figures, accepted for publication in ApJ, GitHub repository for scripts and figures on https://github.com/dmvandam/v928tau</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2010.10753">arXiv:2010.10753</a> <span> [<a href="https://arxiv.org/pdf/2010.10753">pdf</a>, <a href="https://arxiv.org/format/2010.10753">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/abc3be">10.3847/1538-4357/abc3be <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Fermi-LAT Observations of V549 Vel 2017: a Sub-Luminous Gamma-Ray Nova? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Li%2C+K">Kwan-Lok Li</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Munari%2C+U">Ulisse Munari</a>, <a href="/search/astro-ph?searchtype=author&query=Metzger%2C+B+D">Brian D. Metzger</a>, <a href="/search/astro-ph?searchtype=author&query=Chomiuk%2C+L">Laura Chomiuk</a>, <a href="/search/astro-ph?searchtype=author&query=Frigo%2C+A">Andrea Frigo</a>, <a href="/search/astro-ph?searchtype=author&query=Strader%2C+J">Jay Strader</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2010.10753v1-abstract-short" style="display: inline;"> We report on the Fermi-LAT detection (with ~5.7 sigma significance) as well as the multi-wavelength analysis of the 2017 nova eruption V549 Vel. Unlike the recent shock-powered novae ASASSN-16ma and V906 Car, the optical and gamma-ray light curves of V549 Vel show no correlation, likely implying relatively weak shocks in the eruption. Gaia detected a candidate progenitor of V549 Vel and found a pa… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.10753v1-abstract-full').style.display = 'inline'; document.getElementById('2010.10753v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.10753v1-abstract-full" style="display: none;"> We report on the Fermi-LAT detection (with ~5.7 sigma significance) as well as the multi-wavelength analysis of the 2017 nova eruption V549 Vel. Unlike the recent shock-powered novae ASASSN-16ma and V906 Car, the optical and gamma-ray light curves of V549 Vel show no correlation, likely implying relatively weak shocks in the eruption. Gaia detected a candidate progenitor of V549 Vel and found a parallax measurement of 1.91+/-0.39 mas, equivalent to a mode distance of d=560 pc (90% credible interval of 380-1050 pc). The progenitor was also observed by the 2MASS and WISE surveys. When adopting the Gaia distance, the spectral energy distribution of the progenitor is close to that of a G-type star. Swift/XRT detected the supersoft X-ray emission of the nova (kT=30-40 keV) since day 236, and the inferred blackbody size is comparable to that of other novae assuming d=560 pc (i.e., R_bb~5*10^8 cm). However, there is also an unknown astrometric excess noise of 3.2 mas found in the Gaia data, and the inferred distance becomes controversial. If the Gaia distance is accurate, the gamma-ray luminosity of V549 Vel will be as low as L_gamma~4*10^33 erg/s, making it the least luminous gamma-ray nova known so far. This may imply that the shock properties responsible for the gamma-ray emission in V549 Vel are different from those of the more luminous events. If the nova is located farther away, it is likely a symbiotic system with a giant companion as the observed progenitor. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.10753v1-abstract-full').style.display = 'none'; document.getElementById('2010.10753v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, including 5 figures and 1 tables. Accepted for publication in ApJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2010.07812">arXiv:2010.07812</a> <span> [<a href="https://arxiv.org/pdf/2010.07812">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> </div> <p class="title is-5 mathjax"> IM Normae: The Death Spiral of a Cataclysmic Variable? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Patterson%2C+J">Joseph Patterson</a>, <a href="/search/astro-ph?searchtype=author&query=Kemp%2C+J">Jonathan Kemp</a>, <a href="/search/astro-ph?searchtype=author&query=Monard%2C+B">Berto Monard</a>, <a href="/search/astro-ph?searchtype=author&query=Myers%2C+G">Gordon Myers</a>, <a href="/search/astro-ph?searchtype=author&query=de+Miguel%2C+E">Enrique de Miguel</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Warhurst%2C+P">Paul Warhurst</a>, <a href="/search/astro-ph?searchtype=author&query=Rea%2C+R">Robert Rea</a>, <a href="/search/astro-ph?searchtype=author&query=Dvorak%2C+S">Shawn Dvorak</a>, <a href="/search/astro-ph?searchtype=author&query=Menzies%2C+K">Kenneth Menzies</a>, <a href="/search/astro-ph?searchtype=author&query=Vanmunster%2C+T">Tonny Vanmunster</a>, <a href="/search/astro-ph?searchtype=author&query=Roberts%2C+G">George Roberts</a>, <a href="/search/astro-ph?searchtype=author&query=Campbell%2C+T">Tut Campbell</a>, <a href="/search/astro-ph?searchtype=author&query=Starkey%2C+D">Donn Starkey</a>, <a href="/search/astro-ph?searchtype=author&query=Ulowetz%2C+J">Joseph Ulowetz</a>, <a href="/search/astro-ph?searchtype=author&query=Rock%2C+J">John Rock</a>, <a href="/search/astro-ph?searchtype=author&query=Seargeant%2C+J">Jim Seargeant</a>, <a href="/search/astro-ph?searchtype=author&query=Boardman%2C+J">James Boardman</a>, <a href="/search/astro-ph?searchtype=author&query=Lemay%2C+D">Damien Lemay</a>, <a href="/search/astro-ph?searchtype=author&query=Cejudo%2C+D">David Cejudo</a>, <a href="/search/astro-ph?searchtype=author&query=Knigge%2C+C">Christian Knigge</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2010.07812v2-abstract-short" style="display: inline;"> We present a study of the orbital light curves of the recurrent nova IM Normae since its 2002 outburst. The broad "eclipses" recur with a 2.46 hour period, which increases on a timescale of 1.28(16)x10^6 years. Under the assumption of conservative mass-transfer, this suggests a rate near 10^-7 M_sol/year, and this agrees with the estimated /accretion/ rate of the postnova, based on our estimate of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.07812v2-abstract-full').style.display = 'inline'; document.getElementById('2010.07812v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.07812v2-abstract-full" style="display: none;"> We present a study of the orbital light curves of the recurrent nova IM Normae since its 2002 outburst. The broad "eclipses" recur with a 2.46 hour period, which increases on a timescale of 1.28(16)x10^6 years. Under the assumption of conservative mass-transfer, this suggests a rate near 10^-7 M_sol/year, and this agrees with the estimated /accretion/ rate of the postnova, based on our estimate of luminosity. IM Nor appears to be a close match to the famous recurrent nova T Pyxidis. Both stars appear to have very high accretion rates, sufficient to drive the recurrent-nova events. Both have quiescent light curves which suggest strong heating of the low-mass secondary, and very wide orbital minima which suggest obscuration of a large "corona" around the primary. And both have very rapid orbital period increases, as expected from a short-period binary with high mass transfer from the low-mass component. These two stars may represent a final stage of nova -- and cataclysmic-variable -- evolution, in which irradiation-driven winds drive a high rate of mass transfer, thereby evaporating the donor star in a paroxysm of nova outbursts. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.07812v2-abstract-full').style.display = 'none'; document.getElementById('2010.07812v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">PDF, 30 pages, 3 tables, 6 figures; accepted, in press, ApJ; more info at http://cbastro.org/</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2009.09239">arXiv:2009.09239</a> <span> [<a href="https://arxiv.org/pdf/2009.09239">pdf</a>, <a href="https://arxiv.org/ps/2009.09239">ps</a>, <a href="https://arxiv.org/format/2009.09239">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/staa2905">10.1093/mnras/staa2905 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> High-Amplitude gamma Doradus Variables </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Paunzen%2C+E">Ernst Paunzen</a>, <a href="/search/astro-ph?searchtype=author&query=Bernhard%2C+K">Klaus Bernhard</a>, <a href="/search/astro-ph?searchtype=author&query=Huemmerich%2C+S">Stefan Huemmerich</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F">Franz-Josef Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Lloyd%2C+C">Christopher Lloyd</a>, <a href="/search/astro-ph?searchtype=author&query=Otero%2C+S">Sebastian Otero</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2009.09239v2-abstract-short" style="display: inline;"> According to most literature sources, the amplitude of the pulsational variability observed in gamma Doradus stars does not exceed 0.1 mag in Johnson V. We have analyzed fifteen high-amplitude gamma Doradus stars with photometric peak-to-peak amplitudes well beyond this limit, with the aim of unraveling the mechanisms behind the observed high amplitudes and investigating whether these objects are… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.09239v2-abstract-full').style.display = 'inline'; document.getElementById('2009.09239v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.09239v2-abstract-full" style="display: none;"> According to most literature sources, the amplitude of the pulsational variability observed in gamma Doradus stars does not exceed 0.1 mag in Johnson V. We have analyzed fifteen high-amplitude gamma Doradus stars with photometric peak-to-peak amplitudes well beyond this limit, with the aim of unraveling the mechanisms behind the observed high amplitudes and investigating whether these objects are in any way physically distinct from their low-amplitude counterparts. We have calculated astrophysical parameters and investigated the location of the high-amplitude gamma Doradus stars and a control sample of fifteen low-amplitude objects in the log Teff versus log L diagram. Employing survey data and our own observations, we analyzed the photometric variability of our target stars using discrete Fourier transform. Correlations between the observed primary frequencies, amplitudes and other parameters like effective temperature and luminosity were investigated. The unusually high amplitudes of the high-amplitude gamma Doradus stars can be explained by the superposition of several base frequencies in interaction with their combination and overtone frequencies. Although the maximum amplitude of the primary frequencies does not exceed an amplitude of 0.1 mag, total light variability amplitudes of over 0.3 mag (V) can be attained in this way. Low- and high-amplitude gamma Doradus stars do not appear to be physically distinct in any other respect than their total variability amplitudes but merely represent two ends of the same, uniform group of variables. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.09239v2-abstract-full').style.display = 'none'; document.getElementById('2009.09239v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 September, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 11 figures, 19 tables, accepted for Monthly Notices of the Royal Astronomical Society, corrected the format of Table 2</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2006.10449">arXiv:2006.10449</a> <span> [<a href="https://arxiv.org/pdf/2006.10449">pdf</a>, <a href="https://arxiv.org/format/2006.10449">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/staa1817">10.1093/mnras/staa1817 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Compact Triply Eclipsing Triple Star TIC 209409435 Discovered with TESS </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Borkovits%2C+T">T. Borkovits</a>, <a href="/search/astro-ph?searchtype=author&query=Rappaport%2C+S+A">S. A. Rappaport</a>, <a href="/search/astro-ph?searchtype=author&query=Tan%2C+T+G">T. G. Tan</a>, <a href="/search/astro-ph?searchtype=author&query=Gagliano%2C+R">R. Gagliano</a>, <a href="/search/astro-ph?searchtype=author&query=Jacobs%2C+T">T. Jacobs</a>, <a href="/search/astro-ph?searchtype=author&query=Huang%2C+X">X. Huang</a>, <a href="/search/astro-ph?searchtype=author&query=Mitnyan%2C+T">T. Mitnyan</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Kaye%2C+T">T. Kaye</a>, <a href="/search/astro-ph?searchtype=author&query=Maxted%2C+P+F+L">P. F. L. Maxted</a>, <a href="/search/astro-ph?searchtype=author&query=P%C3%A1l%2C+A">A. P谩l</a>, <a href="/search/astro-ph?searchtype=author&query=Schmitt%2C+A+R">A. R. Schmitt</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2006.10449v1-abstract-short" style="display: inline;"> We report the discovery in $TESS$ Sectors 3 and 4 of a compact triply eclipsing triple star system. TIC 209409435 is a previously unknown eclipsing binary with a period of 5.717 days, and the presence of a third star in an outer eccentric orbit of 121.872 day period was found from two sets of third-body eclipses and from eclipse timing variations. The latter exhibit signatures of strong 3rd-body p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.10449v1-abstract-full').style.display = 'inline'; document.getElementById('2006.10449v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2006.10449v1-abstract-full" style="display: none;"> We report the discovery in $TESS$ Sectors 3 and 4 of a compact triply eclipsing triple star system. TIC 209409435 is a previously unknown eclipsing binary with a period of 5.717 days, and the presence of a third star in an outer eccentric orbit of 121.872 day period was found from two sets of third-body eclipses and from eclipse timing variations. The latter exhibit signatures of strong 3rd-body perturbations. After the discovery, we obtained follow-up ground-based photometric observations of several binary eclipses as well as another of the third-body eclipses. We carried out comprehensive analyses, including the simultaneous photodynamical modelling of $TESS$ and ground-based lightcurves (including both archival WASP data, and our own follow-up measurements), as well as eclipse timing variation curves. Also, we have included in the simultaneous fits multiple star spectral energy distribution data and theoretical PARSEC stellar isochrones. We find that the inner binary consists of near twin stars of mass 0.90 $M_\odot$ and radius 0.88 $R_\odot$. The third star is just 9% more massive and 18% larger in radius. The inner binary has a rather small eccentricity while the outer orbit has $e = 0.40$. The inner binary and outer orbit have inclination angles within 0.1$^\circ$ and 0.2$^\circ$ of 90$^\circ$, respectively. The mutual inclination angle is $\lesssim 1/4^\circ$. All of these results were obtained without radial velocity observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.10449v1-abstract-full').style.display = 'none'; document.getElementById('2006.10449v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in MNRAS</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.10135">arXiv:2003.10135</a> <span> [<a href="https://arxiv.org/pdf/2003.10135">pdf</a>, <a href="https://arxiv.org/ps/2003.10135">ps</a>, <a href="https://arxiv.org/format/2003.10135">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/201937199">10.1051/0004-6361/201937199 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The path to Z And-type outbursts: The case of V426 Sagittae (HBHA 1704-05) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Skopal%2C+A">A. Skopal</a>, <a href="/search/astro-ph?searchtype=author&query=Shugarov%2C+S+Y">S. Yu. Shugarov</a>, <a href="/search/astro-ph?searchtype=author&query=Munari%2C+U">U. Munari</a>, <a href="/search/astro-ph?searchtype=author&query=Masetti%2C+N">N. Masetti</a>, <a href="/search/astro-ph?searchtype=author&query=Marchesini%2C+E">E. Marchesini</a>, <a href="/search/astro-ph?searchtype=author&query=Komzik%2C+R+M">R. M. Komzik</a>, <a href="/search/astro-ph?searchtype=author&query=Kundra%2C+E">E. Kundra</a>, <a href="/search/astro-ph?searchtype=author&query=Shagatova%2C+N">N. Shagatova</a>, <a href="/search/astro-ph?searchtype=author&query=Tarasova%2C+T+N">T. N. Tarasova</a>, <a href="/search/astro-ph?searchtype=author&query=Buil%2C+C">C. Buil</a>, <a href="/search/astro-ph?searchtype=author&query=Boussin%2C+C">C. Boussin</a>, <a href="/search/astro-ph?searchtype=author&query=Shenavrin%2C+V+I">V. I. Shenavrin</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=Dallaporta%2C+S">S. Dallaporta</a>, <a href="/search/astro-ph?searchtype=author&query=Frigo%2C+A">A. Frigo</a>, <a href="/search/astro-ph?searchtype=author&query=Garde%2C+O">O. Garde</a>, <a href="/search/astro-ph?searchtype=author&query=Zubareva%2C+A">A. Zubareva</a>, <a href="/search/astro-ph?searchtype=author&query=Dubovsk%C3%BD%2C+P+A">P. A. Dubovsk媒</a>, <a href="/search/astro-ph?searchtype=author&query=Kroll%2C+P">P. Kroll</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2003.10135v2-abstract-short" style="display: inline;"> The star V426 Sge (HBHA~1704-05), originally classified as an emission-line object and a semi-regular variable, brightened at the beginning of August 2018, showing signatures of a symbiotic star outburst. We aim to confirm the nature of V426 Sge as a classical symbiotic star, determine the photometric ephemeris of the light minima, and suggest the path from its 1968 symbiotic nova outburst to the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.10135v2-abstract-full').style.display = 'inline'; document.getElementById('2003.10135v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.10135v2-abstract-full" style="display: none;"> The star V426 Sge (HBHA~1704-05), originally classified as an emission-line object and a semi-regular variable, brightened at the beginning of August 2018, showing signatures of a symbiotic star outburst. We aim to confirm the nature of V426 Sge as a classical symbiotic star, determine the photometric ephemeris of the light minima, and suggest the path from its 1968 symbiotic nova outburst to the following 2018 Z And-type outburst. We re-constructed an historical light curve (LC) of V426 Sge from approximately the year 1900, and used original low- and high-resolution spectroscopy complemented with Swift-XRT and UVOT, optical UBVRcIc and near-infrared JHKL photometry obtained during the 2018 outburst and the following quiescence. The historical LC reveals no symbiotic-like activity from 1900 to 1967. In 1968, V426 Sge experienced a symbiotic nova outburst that ceased around 1990. From approximately 1972, a wave-like orbitally related variation with a period of $493.4\pm 0.7$ days developed in the LC. This was interrupted by a Z And-type outburst from the beginning of August 2018 to the middle of February 2019. At the maximum of the 2018 outburst, the burning white dwarf (WD) increased its temperature to $>2\times 10^5$ K, generated a luminosity of $\sim 7\times 10^{37}(d/3.3kpc)^2$ erg/s, and blew a wind at the rate of $\sim 3\times 10^{-6}$ M$_{\odot}$/yr. The donor is a normal M4-5 III giant and the accretor is a low-mass $\sim$0.5 M$_{\odot}$ WD. During the transition from the symbiotic nova outburst to the quiescent phase, a pronounced sinusoidal variation along the orbit develops in the LC of most symbiotic novae. The following eventual outburst is of Z And-type, when the accretion by the WD temporarily exceeds the upper limit of the stable burning. At this point the system becomes a classical symbiotic star. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.10135v2-abstract-full').style.display = 'none'; document.getElementById('2003.10135v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 12 figures, 9 tables, 2 appendices, accepted for A&A, Tables A.1, A.2 and A.3 are only available at the CDS, added references for section 1</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 636, A77 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.03056">arXiv:2003.03056</a> <span> [<a href="https://arxiv.org/pdf/2003.03056">pdf</a>, <a href="https://arxiv.org/format/2003.03056">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/0004-6361/202037631">10.1051/0004-6361/202037631 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Modelling hystereses observed during dwarf-nova outbursts </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hameury%2C+J+-">J. -M. Hameury</a>, <a href="/search/astro-ph?searchtype=author&query=Knigge%2C+C">C. Knigge</a>, <a href="/search/astro-ph?searchtype=author&query=Lasota%2C+J+-">J. -P. Lasota</a>, <a href="/search/astro-ph?searchtype=author&query=Hambsch%2C+F+-">F. -J. Hambsch</a>, <a href="/search/astro-ph?searchtype=author&query=James%2C+R">R. James</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2003.03056v1-abstract-short" style="display: inline;"> Context. Although the disc instability model is widely accepted as the explanation for dwarf nova outbursts, it is still necessary to confront its predictions to observations because much of the constraints on angular momentum transport in accretion discs are derived from the application of this model to real systems. Aims. We test the predictions of the model concerning the multicolour time evo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.03056v1-abstract-full').style.display = 'inline'; document.getElementById('2003.03056v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.03056v1-abstract-full" style="display: none;"> Context. Although the disc instability model is widely accepted as the explanation for dwarf nova outbursts, it is still necessary to confront its predictions to observations because much of the constraints on angular momentum transport in accretion discs are derived from the application of this model to real systems. Aims. We test the predictions of the model concerning the multicolour time evolution of outbursts for two well--observed systems, SS Cyg and VW Hyi. Methods. We calculate the multicolour evolution of dwarf nova outbursts using the disc instability model and taking into account the contribution from the irradiated secondary, the white dwarf and the hot spot. Results. Observations definitely show the existence of a hysteresis in the optical colour-magnitude diagram during the evolution of dwarf nova outbursts. We find that the disc instability model naturally explains the existence and the orientation of this hysteresis. For the specific cases of SS Cyg and VW Hyi, the colour and magnitude ranges covered during the evolution of the system are in reasonable agreement with observations. However, the observed colours are bluer than observed near the peak of the outbursts -- as in steady systems, and the amplitude of the hysteresis cycle is smaller than observed. The predicted colours significantly depend on the assumptions made for calculating the disc spectrum during rise, and on the magnitude of the secondary irradiation for the decaying part of the outburst. Conclusions. Improvements of the spectral disc models are strongly needed if one wishes to address the system evolution in the UV. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.03056v1-abstract-full').style.display = 'none'; document.getElementById('2003.03056v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Astronomy and Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 636, A1 (2020) </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" 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