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breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Buzasi%2C+D+L&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Buzasi%2C+D+L&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Buzasi%2C+D+L&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </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/2410.23466">arXiv:2410.23466</a> <span> [<a href="https://arxiv.org/pdf/2410.23466">pdf</a>, <a href="https://arxiv.org/format/2410.23466">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="Instrumentation and Methods for Astrophysics">astro-ph.IM</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/stae2418">10.1093/mnras/stae2418 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Polarization position angle standard stars: a reassessment of $胃$ and its variability for seventeen stars based on a decade of observations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cotton%2C+D+V">Daniel V. Cotton</a>, <a href="/search/?searchtype=author&query=Bailey%2C+J">Jeremy Bailey</a>, <a href="/search/?searchtype=author&query=Kedziora-Chudczer%2C+L">Lucyna Kedziora-Chudczer</a>, <a href="/search/?searchtype=author&query=Bott%2C+K">Kimberly Bott</a>, <a href="/search/?searchtype=author&query=De+Horta%2C+A">Ain De Horta</a>, <a href="/search/?searchtype=author&query=Filcek%2C+N">Normandy Filcek</a>, <a href="/search/?searchtype=author&query=Marshall%2C+J+P">Jonathan P. Marshall</a>, <a href="/search/?searchtype=author&query=Melville%2C+G">Graeme Melville</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Boiko%2C+I">Ievgeniia Boiko</a>, <a href="/search/?searchtype=author&query=Borsato%2C+N+W">Nicholas W. Borsato</a>, <a href="/search/?searchtype=author&query=Perkins%2C+J">Jean Perkins</a>, <a href="/search/?searchtype=author&query=Opitz%2C+D">Daniela Opitz</a>, <a href="/search/?searchtype=author&query=Melrose%2C+S">Shannon Melrose</a>, <a href="/search/?searchtype=author&query=Gr%C3%BCning%2C+G">Gesa Gr眉ning</a>, <a href="/search/?searchtype=author&query=Evensberget%2C+D">Dag Evensberget</a>, <a href="/search/?searchtype=author&query=Zhao%2C+J">Jinglin Zhao</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="2410.23466v1-abstract-short" style="display: inline;"> Observations of polarization position angle ($胃$) standards made from 2014 to 2023 with the High Precision Polarimetric Instrument (HIPPI) and other HIPPI-class polarimeters in both hemispheres are used to investigate their variability. Multi-band data were first used to thoroughly recalibrate the instrument performance by bench-marking against carefully selected literature data. A novel Co-ordina… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.23466v1-abstract-full').style.display = 'inline'; document.getElementById('2410.23466v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.23466v1-abstract-full" style="display: none;"> Observations of polarization position angle ($胃$) standards made from 2014 to 2023 with the High Precision Polarimetric Instrument (HIPPI) and other HIPPI-class polarimeters in both hemispheres are used to investigate their variability. Multi-band data were first used to thoroughly recalibrate the instrument performance by bench-marking against carefully selected literature data. A novel Co-ordinate Difference Matrix (CDM) approach - which combines pairs of points - was then used to amalgamate monochromatic ($g^\prime$ band) observations from many observing runs and re-determine $胃$ for 17 standard stars. The CDM algorithm was then integrated into a fitting routine and used to establish the impact of stellar variability on the measured position angle scatter. The approach yields variability detections for stars on long time scales that appear stable over short runs. The best position angle standards are $\ell$ Car, $o$ Sco, HD 154445, HD 161056 and $喂^1$ Sco which are stable to $\leq$ 0.123$^\circ$. Position angle variability of 0.27-0.82$^\circ$, significant at the 3-$蟽$ level, is found for 5 standards, including the Luminous Blue Variable HD 160529 and all but one of the other B/A-type supergiants (HD 80558, HD 111613, HD 183143 and 55 Cyg), most of which also appear likely to be variable in polarization magnitude ($p$) - there is no preferred orientation for the polarization in these objects, which are all classified as $伪$ Cygni variables. Despite this we make six key recommendations for observers - relating to data acquisition, processing and reporting - that will allow them to use these standards to achieve $<$ 0.1$^\circ$ precision in the telescope position angle with similar instrumentation, and allow data sets to be combined more accurately. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.23466v1-abstract-full').style.display = 'none'; document.getElementById('2410.23466v1-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 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">30 pages, 8 figures, 17 tables, 4 appendices; accepted to MNRAS. Companion data at: http://www.mira.org/research/polarimetry/PA</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.17707">arXiv:2404.17707</a> <span> [<a href="https://arxiv.org/pdf/2404.17707">pdf</a>, <a href="https://arxiv.org/format/2404.17707">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"> Deneb is a Large Amplitude Polarimetric Variable </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cotton%2C+D+V">Daniel V. Cotton</a>, <a href="/search/?searchtype=author&query=Bailey%2C+J">Jeremy Bailey</a>, <a href="/search/?searchtype=author&query=Perkins%2C+J">Jean Perkins</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Boiko%2C+I">Ievgeniia Boiko</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="2404.17707v1-abstract-short" style="display: inline;"> We write to report the discovery that Deneb is a large amplitude polarization variable. Over a ~400 d time span from August 2022 Deneb's polarization was typically around 3900 parts-per-million (ppm) in the SDSS g'-band. Yet, it varied by several hundred ppm in an irregular way on a timescale of weeks. The largest polarization change, amounting to 2500 ppm, occurred shortly after the last pulsatio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.17707v1-abstract-full').style.display = 'inline'; document.getElementById('2404.17707v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.17707v1-abstract-full" style="display: none;"> We write to report the discovery that Deneb is a large amplitude polarization variable. Over a ~400 d time span from August 2022 Deneb's polarization was typically around 3900 parts-per-million (ppm) in the SDSS g'-band. Yet, it varied by several hundred ppm in an irregular way on a timescale of weeks. The largest polarization change, amounting to 2500 ppm, occurred shortly after the last pulsation ``resumption'' event identified by Abt et al. (2023) in TESS photometry. The relationship between the observed polarization -- particularly corresponding to the resumption event -- and its brightness and H-alpha spectra suggests a mechanism involving density changes in its wind and/or extended atmosphere. Smaller effects due to pulsations are not ruled out and further study is recommended. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.17707v1-abstract-full').style.display = 'none'; document.getElementById('2404.17707v1-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 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 to ApJL. 7 pages; 2 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/2403.16333">arXiv:2403.16333</a> <span> [<a href="https://arxiv.org/pdf/2403.16333">pdf</a>, <a href="https://arxiv.org/format/2403.16333">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/10.1051/0004-6361/202449197">10.1051/0004-6361/202449197 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Expanding the frontiers of cool-dwarf asteroseismology with ESPRESSO. Detection of solar-like oscillations in the K5 dwarf $蔚$ Indi </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Campante%2C+T+L">T. L. Campante</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a>, <a href="/search/?searchtype=author&query=Li%2C+Y">Y. Li</a>, <a href="/search/?searchtype=author&query=Lund%2C+M+N">M. N. Lund</a>, <a href="/search/?searchtype=author&query=Silva%2C+A+M">A. M. Silva</a>, <a href="/search/?searchtype=author&query=Corsaro%2C+E">E. Corsaro</a>, <a href="/search/?searchtype=author&query=da+Silva%2C+J+G">J. Gomes da Silva</a>, <a href="/search/?searchtype=author&query=Martins%2C+J+H+C">J. H. C. Martins</a>, <a href="/search/?searchtype=author&query=Adibekyan%2C+V">V. Adibekyan</a>, <a href="/search/?searchtype=author&query=Silva%2C+T+A">T. Azevedo Silva</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Bossini%2C+D">D. Bossini</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=Costa%2C+R+R">R. R. Costa</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">M. S. Cunha</a>, <a href="/search/?searchtype=author&query=Cristo%2C+E">E. Cristo</a>, <a href="/search/?searchtype=author&query=Faria%2C+J+P">J. P. Faria</a>, <a href="/search/?searchtype=author&query=Garc%C3%ADa%2C+R+A">R. A. Garc铆a</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">D. Huber</a>, <a href="/search/?searchtype=author&query=Lundkvist%2C+M+S">M. S. Lundkvist</a>, <a href="/search/?searchtype=author&query=Metcalfe%2C+T+S">T. S. Metcalfe</a>, <a href="/search/?searchtype=author&query=Monteiro%2C+M+J+P+F+G">M. J. P. F. G. Monteiro</a>, <a href="/search/?searchtype=author&query=Neitzel%2C+A+W">A. W. Neitzel</a>, <a href="/search/?searchtype=author&query=Nielsen%2C+M+B">M. B. Nielsen</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="2403.16333v1-abstract-short" style="display: inline;"> Fuelled by space photometry, asteroseismology is vastly benefitting the study of cool main-sequence stars, which exhibit convection-driven solar-like oscillations. Even so, the tiny oscillation amplitudes in K dwarfs continue to pose a challenge to space-based asteroseismology. A viable alternative is offered by the lower stellar noise over the oscillation timescales in Doppler observations. In th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.16333v1-abstract-full').style.display = 'inline'; document.getElementById('2403.16333v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.16333v1-abstract-full" style="display: none;"> Fuelled by space photometry, asteroseismology is vastly benefitting the study of cool main-sequence stars, which exhibit convection-driven solar-like oscillations. Even so, the tiny oscillation amplitudes in K dwarfs continue to pose a challenge to space-based asteroseismology. A viable alternative is offered by the lower stellar noise over the oscillation timescales in Doppler observations. In this letter we present the definite detection of solar-like oscillations in the bright K5 dwarf $蔚$ Indi based on time-intensive observations collected with the ESPRESSO spectrograph at the VLT, thus making it the coolest seismic dwarf ever observed. We measured the frequencies of a total of 19 modes of degree $\ell=0$--2 along with $谓_{\rm max}=5305\pm176\:{\rm 渭Hz}$ and $螖谓=201.25\pm0.16\:{\rm 渭Hz}$. The peak amplitude of radial modes is $2.6\pm0.5\:{\rm cm\,s^{-1}}$, or a mere ${\sim} 14\%$ of the solar value. Measured mode amplitudes are ${\sim} 2$ times lower than predicted from a nominal $L/M$ scaling relation and favour a scaling closer to $(L/M)^{1.5}$ below ${\sim} 5500\:{\rm K}$, carrying important implications for our understanding of the coupling efficiency between pulsations and near-surface convection in K dwarfs. This detection conclusively shows that precise asteroseismology of cool dwarfs is possible down to at least the mid-K regime using next-generation spectrographs on large-aperture telescopes, effectively opening up a new domain in observational asteroseismology. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.16333v1-abstract-full').style.display = 'none'; document.getElementById('2403.16333v1-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 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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 Astronomy & Astrophysics Letters</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A, 683, L16 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.04199">arXiv:2312.04199</a> <span> [<a href="https://arxiv.org/pdf/2312.04199">pdf</a>, <a href="https://arxiv.org/ps/2312.04199">ps</a>, <a href="https://arxiv.org/format/2312.04199">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"> TESS Cycle 2 observations of roAp stars with 2-min cadence data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Holdsworth%2C+D+L">D. L. Holdsworth</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">M. S. Cunha</a>, <a href="/search/?searchtype=author&query=Lares-Martiz%2C+M">M. Lares-Martiz</a>, <a href="/search/?searchtype=author&query=Kurtz%2C+D+W">D. W. Kurtz</a>, <a href="/search/?searchtype=author&query=Antoci%2C+V">V. Antoci</a>, <a href="/search/?searchtype=author&query=Forteza%2C+S+B">S. Barcel贸 Forteza</a>, <a href="/search/?searchtype=author&query=De+Cat%2C+P">P. De Cat</a>, <a href="/search/?searchtype=author&query=Derekas%2C+A">A. Derekas</a>, <a href="/search/?searchtype=author&query=Kayhan%2C+C">C. Kayhan</a>, <a href="/search/?searchtype=author&query=Ozuyar%2C+D">D. Ozuyar</a>, <a href="/search/?searchtype=author&query=Skarka%2C+M">M. Skarka</a>, <a href="/search/?searchtype=author&query=Hey%2C+D+R">D. R. Hey</a>, <a href="/search/?searchtype=author&query=Shi%2C+F">F. Shi</a>, <a href="/search/?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/?searchtype=author&query=Kobzar%2C+O">O. Kobzar</a>, <a href="/search/?searchtype=author&query=G%C3%B3mez%2C+A+A">A. Ayala G贸mez</a>, <a href="/search/?searchtype=author&query=Bogn%C3%A1r%2C+Z">Zs. Bogn谩r</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Ebadi%2C+M">M. Ebadi</a>, <a href="/search/?searchtype=author&query=Fox-Machado%2C+L">L. Fox-Machado</a>, <a href="/search/?searchtype=author&query=Hern%C3%A1ndez%2C+A+G">A. Garc铆a Hern谩ndez</a>, <a href="/search/?searchtype=author&query=Ghasemi%2C+H">H. Ghasemi</a>, <a href="/search/?searchtype=author&query=Guzik%2C+J+A">J. A. Guzik</a>, <a href="/search/?searchtype=author&query=Handberg%2C+R">R. Handberg</a>, <a href="/search/?searchtype=author&query=Handler%2C+G">G. Handler</a> , et al. (24 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="2312.04199v1-abstract-short" style="display: inline;"> We present the results of a systematic search of the Transiting Exoplanet Survey Satellite (TESS) 2-min cadence data for new rapidly oscillating Ap (roAp) stars observed during the Cycle 2 phase of its mission. We find seven new roAp stars previously unreported as such and present the analysis of a further 25 roAp stars that are already known. Three of the new stars show multiperiodic pulsations,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.04199v1-abstract-full').style.display = 'inline'; document.getElementById('2312.04199v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.04199v1-abstract-full" style="display: none;"> We present the results of a systematic search of the Transiting Exoplanet Survey Satellite (TESS) 2-min cadence data for new rapidly oscillating Ap (roAp) stars observed during the Cycle 2 phase of its mission. We find seven new roAp stars previously unreported as such and present the analysis of a further 25 roAp stars that are already known. Three of the new stars show multiperiodic pulsations, while all new members are rotationally variable stars, leading to almost 70 per cent (22) of the roAp stars presented being $伪^2$ CVn-type variable stars. We show that targeted observations of known chemically peculiar stars are likely to overlook many new roAp stars, and demonstrate that multi-epoch observations are necessary to see pulsational behaviour changes. We find a lack of roAp stars close to the blue edge of the theoretical roAp instability strip, and reaffirm that mode instability is observed more frequently with precise, space-based observations. In addition to the Cycle 2 observations, we analyse TESS data for all known roAp stars. This amounts to 18 further roAp stars observed by TESS. Finally, we list six known roAp stars that TESS is yet to observe. We deduce that the incidence of roAp stars amongst the Ap star population is just 5.5 per cent, raising fundamental questions about the conditions required to excite pulsations in Ap stars. This work, coupled with our previous work on roAp stars in Cycle 1 observations, presents the most comprehensive, homogeneous study of the roAp stars in the TESS nominal mission, with a collection of 112 confirmed roAp stars in total. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.04199v1-abstract-full').style.display = 'none'; document.getElementById('2312.04199v1-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 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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 in MNRAS. 32 Pages, 2 Tables, 77 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/2304.01570">arXiv:2304.01570</a> <span> [<a href="https://arxiv.org/pdf/2304.01570">pdf</a>, <a href="https://arxiv.org/format/2304.01570">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/acc9c1">10.3847/1538-3881/acc9c1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Revisiting the Red-giant Branch Hosts KOI-3886 and $喂$ Draconis. Detailed Asteroseismic Modeling and Consolidated Stellar Parameters </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Campante%2C+T+L">Tiago L. Campante</a>, <a href="/search/?searchtype=author&query=Li%2C+T">Tanda Li</a>, <a href="/search/?searchtype=author&query=Ong%2C+J+M+J">J. M. Joel Ong</a>, <a href="/search/?searchtype=author&query=Corsaro%2C+E">Enrico Corsaro</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">Margarida S. Cunha</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Bossini%2C+D">Diego Bossini</a>, <a href="/search/?searchtype=author&query=Breton%2C+S+N">Sylvain N. Breton</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Deal%2C+M">Morgan Deal</a>, <a href="/search/?searchtype=author&query=Garc%C3%ADa%2C+R+A">Rafael A. Garc铆a</a>, <a href="/search/?searchtype=author&query=Hill%2C+M+L">Michelle L. Hill</a>, <a href="/search/?searchtype=author&query=Hon%2C+M">Marc Hon</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Jiang%2C+C">Chen Jiang</a>, <a href="/search/?searchtype=author&query=Kane%2C+S+R">Stephen R. Kane</a>, <a href="/search/?searchtype=author&query=Kayhan%2C+C">Cenk Kayhan</a>, <a href="/search/?searchtype=author&query=Kuszlewicz%2C+J+S">James S. Kuszlewicz</a>, <a href="/search/?searchtype=author&query=Lillo-Box%2C+J">Jorge Lillo-Box</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">Savita Mathur</a>, <a href="/search/?searchtype=author&query=Monteiro%2C+M+J+P+F+G">M谩rio J. P. F. G. Monteiro</a>, <a href="/search/?searchtype=author&query=Pereira%2C+F">Filipe Pereira</a>, <a href="/search/?searchtype=author&query=Santos%2C+N+C">Nuno C. Santos</a>, <a href="/search/?searchtype=author&query=Serenelli%2C+A">Aldo Serenelli</a> , et al. (1 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="2304.01570v1-abstract-short" style="display: inline;"> Asteroseismology is playing an increasingly important role in the characterization of red-giant host stars and their planetary systems. Here, we conduct detailed asteroseismic modeling of the evolved red-giant branch (RGB) hosts KOI-3886 and $喂$ Draconis, making use of end-of-mission Kepler (KOI-3886) and multi-sector TESS ($喂$ Draconis) time-series photometry. We also model the benchmark star KIC… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.01570v1-abstract-full').style.display = 'inline'; document.getElementById('2304.01570v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.01570v1-abstract-full" style="display: none;"> Asteroseismology is playing an increasingly important role in the characterization of red-giant host stars and their planetary systems. Here, we conduct detailed asteroseismic modeling of the evolved red-giant branch (RGB) hosts KOI-3886 and $喂$ Draconis, making use of end-of-mission Kepler (KOI-3886) and multi-sector TESS ($喂$ Draconis) time-series photometry. We also model the benchmark star KIC 8410637, a member of an eclipsing binary, thus providing a direct test to the seismic determination. We test the impact of adopting different sets of observed modes as seismic constraints. Inclusion of $\ell=1$ and 2 modes improves the precision on the stellar parameters, albeit marginally, compared to adopting radial modes alone, with $1.9$-$3.0\%$ (radius), $5$-$9\%$ (mass), and $19$-$25\%$ (age) reached when using all p-dominated modes as constraints. Given the very small spacing of adjacent dipole mixed modes in evolved RGB stars, the sparse set of observed g-dominated modes is not able to provide extra constraints, further leading to highly multimodal posteriors. Access to multi-year time-series photometry does not improve matters, with detailed modeling of evolved RGB stars based on (lower-resolution) TESS data sets attaining a precision commensurate with that based on end-of-mission Kepler data. Furthermore, we test the impact of varying the atmospheric boundary condition in our stellar models. We find mass and radius estimates to be insensitive to the description of the near-surface layers, at the expense of substantially changing both the near-surface structure of the best-fitting models and the values of associated parameters like the initial helium abundance, $Y_{\rm i}$. Attempts to measure $Y_{\rm i}$ from seismic modeling of red giants may thus be systematically dependent on the choice of atmospheric physics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.01570v1-abstract-full').style.display = 'none'; document.getElementById('2304.01570v1-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 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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 in The Astronomical Journal (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/2302.01102">arXiv:2302.01102</a> <span> [<a href="https://arxiv.org/pdf/2302.01102">pdf</a>, <a href="https://arxiv.org/format/2302.01102">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/acb8ac">10.3847/1538-4357/acb8ac <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> TESS Asteroseismic Analysis of HD 76920: The Giant Star Hosting An Extremely Eccentric Exoplanet </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Jiang%2C+C">Chen Jiang</a>, <a href="/search/?searchtype=author&query=Wu%2C+T">Tao Wu</a>, <a href="/search/?searchtype=author&query=Feinstein%2C+A+D">Adina D. Feinstein</a>, <a href="/search/?searchtype=author&query=Stassun%2C+K+G">Keivan G. Stassun</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Veras%2C+D">Dimitri Veras</a>, <a href="/search/?searchtype=author&query=Corsaro%2C+E">Enrico Corsaro</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">Dennis Stello</a>, <a href="/search/?searchtype=author&query=Li%2C+Y">Yaguang Li</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">Savita Mathur</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">Rafael A. Garcia</a>, <a href="/search/?searchtype=author&query=Breton%2C+S+N">Sylvain N. Breton</a>, <a href="/search/?searchtype=author&query=Lundkvist%2C+M+S">Mia S. Lundkvist</a>, <a href="/search/?searchtype=author&query=Mikolajczyk%2C+P+J">Przemyslaw J. Mikolajczyk</a>, <a href="/search/?searchtype=author&query=Gehan%2C+C">Charlotte Gehan</a>, <a href="/search/?searchtype=author&query=Campante%2C+T+L">Tiago L. Campante</a>, <a href="/search/?searchtype=author&query=Bossini%2C+D">Diego Bossini</a>, <a href="/search/?searchtype=author&query=Kane%2C+S+R">Stephen R. Kane</a>, <a href="/search/?searchtype=author&query=Ong%2C+J+M+J">Jia Mian Joel Ong</a>, <a href="/search/?searchtype=author&query=Yildiz%2C+M">Mutlu Yildiz</a>, <a href="/search/?searchtype=author&query=Kayhan%2C+C">Cenk Kayhan</a>, <a href="/search/?searchtype=author&query=Orhan%2C+Z+C">Zeynep Celik Orhan</a>, <a href="/search/?searchtype=author&query=Ortel%2C+S">Sibel Ortel</a>, <a href="/search/?searchtype=author&query=Zhang%2C+X">Xinyi Zhang</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="2302.01102v2-abstract-short" style="display: inline;"> The Transiting Exoplanet Survey Satellite (TESS) mission searches for new exoplanets. The observing strategy of TESS results in high-precision photometry of millions of stars across the sky, allowing for detailed asteroseismic studies of individual systems. In this work, we present a detailed asteroseismic analysis of the giant star HD 76920 hosting a highly eccentric giant planet ($e = 0.878$) wi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.01102v2-abstract-full').style.display = 'inline'; document.getElementById('2302.01102v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.01102v2-abstract-full" style="display: none;"> The Transiting Exoplanet Survey Satellite (TESS) mission searches for new exoplanets. The observing strategy of TESS results in high-precision photometry of millions of stars across the sky, allowing for detailed asteroseismic studies of individual systems. In this work, we present a detailed asteroseismic analysis of the giant star HD 76920 hosting a highly eccentric giant planet ($e = 0.878$) with an orbital period of 415 days, using 5 sectors of TESS light curve that cover around 140 days of data. Solar-like oscillations in HD 76920 are detected around $52 \, 渭$Hz by TESS for the first time. By utilizing asteroseismic modeling that takes classical observational parameters and stellar oscillation frequencies as constraints, we determine improved measurements of the stellar mass ($1.22 \pm 0.11\, M_\odot$), radius ($8.68 \pm 0.34\,R_\odot$), and age ($5.2 \pm 1.4\,$Gyr). With the updated parameters of the host star, we update the semi-major axis and mass of the planet as $a=1.165 \pm 0.035$ au and $M_{\rm p}\sin{i} = 3.57 \pm 0.22\,M_{\rm Jup}$. With an orbital pericenter of $0.142 \pm 0.005$ au, we confirm that the planet is currently far away enough from the star to experience negligible tidal decay until being engulfed in the stellar envelope. We also confirm that this event will occur within about 100\,Myr, depending on the stellar model used. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.01102v2-abstract-full').style.display = 'none'; document.getElementById('2302.01102v2-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">v1</span> submitted 2 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">18 pages, 7 figures, 4 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/2210.09109">arXiv:2210.09109</a> <span> [<a href="https://arxiv.org/pdf/2210.09109">pdf</a>, <a href="https://arxiv.org/format/2210.09109">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/10.1051/0004-6361/202244579">10.1051/0004-6361/202244579 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Catalogue of Solar-Like Oscillators Observed by TESS in 120-second and 20-second Cadence </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Hatt%2C+E">Emily Hatt</a>, <a href="/search/?searchtype=author&query=Nielsen%2C+M+B">Martin B. Nielsen</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Ball%2C+W+H">Warrick H. Ball</a>, <a href="/search/?searchtype=author&query=Davies%2C+G+R">Guy R. Davies</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Chontos%2C+A">Ashley Chontos</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Kayhan%2C+C">Cenk Kayhan</a>, <a href="/search/?searchtype=author&query=Li%2C+Y">Yaguang Li</a>, <a href="/search/?searchtype=author&query=White%2C+T+R">Timothy R. White</a>, <a href="/search/?searchtype=author&query=Cheng%2C+C">Chen Cheng</a>, <a href="/search/?searchtype=author&query=Metcalfe%2C+T+S">Travis S. Metcalfe</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">Dennis Stello</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="2210.09109v1-abstract-short" style="display: inline;"> The Transiting Exoplanet Survey Satellite (TESS) mission has provided photometric light curves for stars across nearly the entire sky. This allows for the application of asteroseismology to a pool of potential solar-like oscillators that is unprecedented in size. We aim to produce a catalogue of solar-like oscillators observed by TESS in the 120-second and 20-second cadence modes. The catalogue is… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.09109v1-abstract-full').style.display = 'inline'; document.getElementById('2210.09109v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.09109v1-abstract-full" style="display: none;"> The Transiting Exoplanet Survey Satellite (TESS) mission has provided photometric light curves for stars across nearly the entire sky. This allows for the application of asteroseismology to a pool of potential solar-like oscillators that is unprecedented in size. We aim to produce a catalogue of solar-like oscillators observed by TESS in the 120-second and 20-second cadence modes. The catalogue is intended to highlight stars oscillating at frequencies above the TESS 30-minute cadence Nyquist frequency with the purpose of encompassing the main sequence and subgiant evolutionary phases. We aim to provide estimates for the global asteroseismic parameters $谓_{\mathrm{max}}$ and $螖谓$. We apply a new probabilistic detection algorithm to the 120-second and 20-second light curves of over 250,000 stars. This algorithm flags targets that show characteristic signatures of solar-like oscillations. We manually vet the resulting list of targets to confirm the presence of solar-like oscillations. Using the probability densities computed by the algorithm, we measure the global asteroseismic parameters $谓_{\mathrm{max}}$ and $螖谓$. We produce a catalogue of 4,177 solar-like oscillators, reporting $螖谓$ and $谓_{\mathrm{max}}$ for $98\%$ of the total star count. The asteroseismic data reveals vast coverage of the HR diagram, populating the red giant branch, the subgiant regime and extending toward the main sequence. A crossmatch with external catalogs shows that 25 of the detected solar-like oscillators are a component of a spectroscopic binary, and 28 are confirmed planet host stars. These results provide the potential for precise, independent asteroseismic constraints on these and any additional TESS targets of interest. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.09109v1-abstract-full').style.display = 'none'; document.getElementById('2210.09109v1-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 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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 at Astronomy & Astrophysics, 11 pages, 11 figures, online material to be made available</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.12752">arXiv:2209.12752</a> <span> [<a href="https://arxiv.org/pdf/2209.12752">pdf</a>, <a href="https://arxiv.org/format/2209.12752">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/ac8f44">10.3847/1538-4357/ac8f44 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the characterization of GJ 504: a magnetically active planet-host star observed by the Transiting Exoplanet Survey Satellite (TESS) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Di+Mauro%2C+M+P">Maria Pia Di Mauro</a>, <a href="/search/?searchtype=author&query=Reda%2C+R">Raffaele Reda</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">Savita Mathur</a>, <a href="/search/?searchtype=author&query=Garc%C3%ADa%2C+R+A">Rafael A. Garc铆a</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Corsaro%2C+E">Enrico Corsaro</a>, <a href="/search/?searchtype=author&query=Benomar%2C+O">Othman Benomar</a>, <a href="/search/?searchtype=author&query=Cuesta%2C+L+G">Luc铆a Gonz谩lez Cuesta</a>, <a href="/search/?searchtype=author&query=Stassun%2C+K+G">Keivan G. Stassun</a>, <a href="/search/?searchtype=author&query=Benatti%2C+S">Serena Benatti</a>, <a href="/search/?searchtype=author&query=Giovannelli%2C+L">Luca Giovannelli</a>, <a href="/search/?searchtype=author&query=Mesa%2C+D">Dino Mesa</a>, <a href="/search/?searchtype=author&query=Nardetto%2C+N">Nicolas Nardetto</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="2209.12752v1-abstract-short" style="display: inline;"> We present the results of the analysis of the photometric data collected in long and short-cadence mode by the Transiting Exoplanet Survey Satellite (TESS) for GJ 504, a well studied planet-hosting solar-like star, whose fundamental parameters have been largely debated during the last decade. Several attempts have been made by the present authors to isolate the oscillatory properties expected on t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.12752v1-abstract-full').style.display = 'inline'; document.getElementById('2209.12752v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.12752v1-abstract-full" style="display: none;"> We present the results of the analysis of the photometric data collected in long and short-cadence mode by the Transiting Exoplanet Survey Satellite (TESS) for GJ 504, a well studied planet-hosting solar-like star, whose fundamental parameters have been largely debated during the last decade. Several attempts have been made by the present authors to isolate the oscillatory properties expected on this main-sequence star, but we did not find any presence of solar-like pulsations. The suppression of the amplitude of the acoustic modes can be explained by the high level of magnetic activity revealed for this target, not only by the study of the photometric light-curve, but also by the analysis of three decades available of Mount Wilson spectroscopic data. In particular, our measurements of the stellar rotational period Prot=3.4 d and of the main principal magnetic cycle of 12 a confirm previous findings and allow us to locate this star in the early main sequence phase of its evolution during which the chromospheric activity is dominated by the superposition of several cycles before the transition to the phase of the magnetic-braking shutdown with the subsequent decrease of the magnetic activity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.12752v1-abstract-full').style.display = 'none'; document.getElementById('2209.12752v1-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 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.02302">arXiv:2208.02302</a> <span> [<a href="https://arxiv.org/pdf/2208.02302">pdf</a>, <a href="https://arxiv.org/format/2208.02302">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/stac2212">10.1093/mnras/stac2212 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Solar-like oscillations and ellipsoidal variations in TESS observations of the binary 12 Bo枚tis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Ball%2C+W+H">Warrick H. Ball</a>, <a href="/search/?searchtype=author&query=Miglio%2C+A">Andrea Miglio</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Stassun%2C+K+G">Keivan G. Stassun</a>, <a href="/search/?searchtype=author&query=Garc%C3%ADa%2C+R">Rafael Garc铆a</a>, <a href="/search/?searchtype=author&query=Gonz%C3%A1lez-Cuesta%2C+L">Lucia Gonz谩lez-Cuesta</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">Savita Mathur</a>, <a href="/search/?searchtype=author&query=Appourchaux%2C+T">Thierry Appourchaux</a>, <a href="/search/?searchtype=author&query=Benomar%2C+O">Othman Benomar</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Jiang%2C+C">Chen Jiang</a>, <a href="/search/?searchtype=author&query=Kayhan%2C+C">Cenk Kayhan</a>, <a href="/search/?searchtype=author&query=%C3%96rtel%2C+S">Sibel 脰rtel</a>, <a href="/search/?searchtype=author&query=Orhan%2C+Z+%C3%87">Zeynep 脟elik Orhan</a>, <a href="/search/?searchtype=author&query=Y%C4%B1ld%C4%B1z%2C+M">Mutlu Y谋ld谋z</a>, <a href="/search/?searchtype=author&query=Ong%2C+J+M+J">J. M. Joel Ong</a>, <a href="/search/?searchtype=author&query=Basu%2C+S">Sarbani Basu</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="2208.02302v1-abstract-short" style="display: inline;"> Binary stars in which oscillations can be studied in either or both components can provide powerful constraints on our understanding of stellar physics. The bright binary 12 Bo枚tis (12 Boo) is a particularly promising system because the primary is roughly 60 per cent brighter than the secondary despite being only a few per cent more massive. Both stars have substantial surface convection zones and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.02302v1-abstract-full').style.display = 'inline'; document.getElementById('2208.02302v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.02302v1-abstract-full" style="display: none;"> Binary stars in which oscillations can be studied in either or both components can provide powerful constraints on our understanding of stellar physics. The bright binary 12 Bo枚tis (12 Boo) is a particularly promising system because the primary is roughly 60 per cent brighter than the secondary despite being only a few per cent more massive. Both stars have substantial surface convection zones and are therefore, presumably, solar-like oscillators. We report here the first detection of solar-like oscillations and ellipsoidal variations in the TESS light curve of 12 Boo. Though the solar-like oscillations are not clear enough to unambiguously measure individual mode frequencies, we combine global asteroseismic parameters and a precise fit to the spectral energy distribution (SED) to provide new constraints on the properties of the system that are several times more precise than values in the literature. The SED fit alone provides new effective temperatures, luminosities and radii of $6115\pm45\,\mathrm{K}$, $7.531\pm0.110\,\mathrm{L}_\odot$ and $2.450\pm0.045\,\mathrm{R}_\odot$ for 12 Boo A and $6200\pm60\,\mathrm{K}$, $4.692\pm0.095\,\mathrm{L}_\odot$ and $1.901\pm0.045\,\mathrm{R}_\odot$ for 12 Boo B. When combined with our asteroseismic constraints on 12 Boo A, we obtain an age of $2.67^{+0.12}_{-0.16}\,\mathrm{Gyr}$, which is consistent with that of 12 Boo B. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.02302v1-abstract-full').style.display = 'none'; document.getElementById('2208.02302v1-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 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 MNRAS. 6 pages, 4 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/2205.11679">arXiv:2205.11679</a> <span> [<a href="https://arxiv.org/pdf/2205.11679">pdf</a>, <a href="https://arxiv.org/format/2205.11679">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="Instrumentation and Methods for Astrophysics">astro-ph.IM</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/10.1038/s41550-021-01531-9">10.1038/s41550-021-01531-9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Polarimetric detection of nonradial oscillation modes in the beta Cephei star beta Crucis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cotton%2C+D+V">Daniel V. Cotton</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Aerts%2C+C">Conny Aerts</a>, <a href="/search/?searchtype=author&query=Bailey%2C+J">Jeremy Bailey</a>, <a href="/search/?searchtype=author&query=Burssens%2C+S">Siemen Burssens</a>, <a href="/search/?searchtype=author&query=Pedersen%2C+M+G">May G. Pedersen</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">Dennis Stello</a>, <a href="/search/?searchtype=author&query=Kedziora-Chudczer%2C+L">Lucyna Kedziora-Chudczer</a>, <a href="/search/?searchtype=author&query=De+Horta%2C+A">Ain De Horta</a>, <a href="/search/?searchtype=author&query=De+Cat%2C+P">Peter De Cat</a>, <a href="/search/?searchtype=author&query=Lewis%2C+F">Fiona Lewis</a>, <a href="/search/?searchtype=author&query=Malla%2C+S+P">Sai Prathyusha Malla</a>, <a href="/search/?searchtype=author&query=Wright%2C+D+J">Duncan J. Wright</a>, <a href="/search/?searchtype=author&query=Bott%2C+K">Kimberly Bott</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="2205.11679v1-abstract-short" style="display: inline;"> Here we report the detection of polarization variations due to nonradial modes in the beta Cephei star beta Crucis. In so doing we confirm 40-year-old predictions of pulsation-induced polarization variability and its utility in asteroseismology for mode identification. In an approach suited to other beta Cep stars, we combine polarimetry with space-based photometry and archival spectroscopy to ide… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.11679v1-abstract-full').style.display = 'inline'; document.getElementById('2205.11679v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.11679v1-abstract-full" style="display: none;"> Here we report the detection of polarization variations due to nonradial modes in the beta Cephei star beta Crucis. In so doing we confirm 40-year-old predictions of pulsation-induced polarization variability and its utility in asteroseismology for mode identification. In an approach suited to other beta Cep stars, we combine polarimetry with space-based photometry and archival spectroscopy to identify the dominant nonradial mode in polarimetry, f2, as l = 3, m = -3 (in the m-convention of Dziembowski) and determine the stellar axis position angle as 25 (or 205) +/- 8 deg. The rotation axis inclination to the line of sight was derived as approx. 46 deg. from combined polarimetry and spectroscopy, facilitating identification of additional modes and allowing for asteroseismic modelling. This reveals a star of 14.5 +/- 0.5 Solar masses and a convective core containing approx. 28% of its mass -- making beta Crucis the most massive star with an asteroseismic age. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.11679v1-abstract-full').style.display = 'none'; document.getElementById('2205.11679v1-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">33 pages, 11 figures, 8 tables (incl. Supplementary Information). Accepted version; published as Cotton et al. (2022), Nature Astro., Vol 6, pp 154-164. Data is available through VizieR as: J/other/NatAs/6.154. Two explainer articles are available: Cotton & Buzasi (2022), Nature Astro., Vol 6, pp 24-25; Baade (2022), Nature Astro., Vol 6, pp 20-21</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Astronomy, Vol 6, pages 154-164 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.11780">arXiv:2108.11780</a> <span> [<a href="https://arxiv.org/pdf/2108.11780">pdf</a>, <a href="https://arxiv.org/format/2108.11780">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="Earth and Planetary Astrophysics">astro-ph.EP</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/10.3847/1538-4365/ac214a">10.3847/1538-4365/ac214a <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> TESS Data for Asteroseismology: Light Curve Systematics Correction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Lund%2C+M+N">Mikkel N. Lund</a>, <a href="/search/?searchtype=author&query=Handberg%2C+R">Rasmus Handberg</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Carboneau%2C+L">Lindsey Carboneau</a>, <a href="/search/?searchtype=author&query=Hall%2C+O+J">Oliver J. Hall</a>, <a href="/search/?searchtype=author&query=Pereira%2C+F">Filipe Pereira</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Hey%2C+D">Daniel Hey</a>, <a href="/search/?searchtype=author&query=Van+Reeth%2C+T">Timothy Van Reeth</a>, <a href="/search/?searchtype=author&query=collaboration%2C+T">T'DA collaboration</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="2108.11780v1-abstract-short" style="display: inline;"> Data from the Transiting Exoplanet Survey Satellite (TESS) has produced of order one million light curves at cadences of 120 s and especially 1800 s for every ~27-day observing sector during its two-year nominal mission. These data constitute a treasure trove for the study of stellar variability and exoplanets. However, to fully utilize the data in such studies a proper removal of systematic noise… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.11780v1-abstract-full').style.display = 'inline'; document.getElementById('2108.11780v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.11780v1-abstract-full" style="display: none;"> Data from the Transiting Exoplanet Survey Satellite (TESS) has produced of order one million light curves at cadences of 120 s and especially 1800 s for every ~27-day observing sector during its two-year nominal mission. These data constitute a treasure trove for the study of stellar variability and exoplanets. However, to fully utilize the data in such studies a proper removal of systematic noise sources must be performed before any analysis. The TESS Data for Asteroseismology (T'DA) group is tasked with providing analysis-ready data for the TESS Asteroseismic Science Consortium, which covers the full spectrum of stellar variability types, including stellar oscillations and pulsations, spanning a wide range of variability timescales and amplitudes. We present here the two current implementations for co-trending of raw photometric light curves from TESS, which cover different regimes of variability to serve the entire seismic community. We find performance in terms of commonly used noise statistics to meet expectations and to be applicable to a wide range of different intrinsic variability types. Further, we find that the correction of light curves from a full sector of data can be completed well within a few days, meaning that when running in steady-state our routines are able to process one sector before data from the next arrives. Our pipeline is open-source and all processed data will be made available on TASOC and MAST. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.11780v1-abstract-full').style.display = 'none'; document.getElementById('2108.11780v1-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 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">27 pages, 15 figures, accepted for publication in The Astrophysical Journal Supplement Series</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.09109">arXiv:2108.09109</a> <span> [<a href="https://arxiv.org/pdf/2108.09109">pdf</a>, <a href="https://arxiv.org/format/2108.09109">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/ac3000">10.3847/1538-3881/ac3000 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A 20-Second Cadence View of Solar-Type Stars and Their Planets with TESS: Asteroseismology of Solar Analogs and a Re-characterization of pi Men c </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=White%2C+T+R">Timothy R. White</a>, <a href="/search/?searchtype=author&query=Metcalfe%2C+T+S">Travis S. Metcalfe</a>, <a href="/search/?searchtype=author&query=Chontos%2C+A">Ashley Chontos</a>, <a href="/search/?searchtype=author&query=Fausnaugh%2C+M+M">Michael M. Fausnaugh</a>, <a href="/search/?searchtype=author&query=Ho%2C+C+S+K">Cynthia S. K. Ho</a>, <a href="/search/?searchtype=author&query=Van+Eylen%2C+V">Vincent Van Eylen</a>, <a href="/search/?searchtype=author&query=Ball%2C+W">Warrick Ball</a>, <a href="/search/?searchtype=author&query=Basu%2C+S">Sarbani Basu</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Benomar%2C+O">Othman Benomar</a>, <a href="/search/?searchtype=author&query=Bossini%2C+D">Diego Bossini</a>, <a href="/search/?searchtype=author&query=Breton%2C+S">Sylvain Breton</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Campante%2C+T+L">Tiago L. Campante</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">Joergen Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">Margarida S. Cunha</a>, <a href="/search/?searchtype=author&query=Deal%2C+M">Morgan Deal</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">Rafael A. Garcia</a>, <a href="/search/?searchtype=author&query=Munoz%2C+A+G">Antonio Garcia Munoz</a>, <a href="/search/?searchtype=author&query=Gehan%2C+C">Charlotte Gehan</a>, <a href="/search/?searchtype=author&query=Gonzalez-Cuesta%2C+L">Lucia Gonzalez-Cuesta</a>, <a href="/search/?searchtype=author&query=Jiang%2C+C">Chen Jiang</a>, <a href="/search/?searchtype=author&query=Kayhan%2C+C">Cenk Kayhan</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="2108.09109v2-abstract-short" style="display: inline;"> We present an analysis of the first 20-second cadence light curves obtained by the TESS space telescope during its extended mission. We find a precision improvement of 20-second data compared to 2-minute data for bright stars when binned to the same cadence (~10-25% better for T<~8 mag, reaching equal precision at T~13 mag), consistent with pre-flight expectations based on differences in cosmic ra… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.09109v2-abstract-full').style.display = 'inline'; document.getElementById('2108.09109v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.09109v2-abstract-full" style="display: none;"> We present an analysis of the first 20-second cadence light curves obtained by the TESS space telescope during its extended mission. We find a precision improvement of 20-second data compared to 2-minute data for bright stars when binned to the same cadence (~10-25% better for T<~8 mag, reaching equal precision at T~13 mag), consistent with pre-flight expectations based on differences in cosmic ray mitigation algorithms. We present two results enabled by this improvement. First, we use 20-second data to detect oscillations in three solar analogs (gamma Pav, zeta Tuc and pi Men) and use asteroseismology to measure their radii, masses, densities and ages to ~1%, ~3%, ~1% and ~20% respectively, including systematic errors. Combining our asteroseismic ages with chromospheric activity measurements we find evidence that the spread in the activity-age relation is linked to stellar mass and thus convection-zone depth. Second, we combine 20-second data and published radial velocities to re-characterize pi Men c, which is now the closest transiting exoplanet for which detailed asteroseismology of the host star is possible. We show that pi Men c is located at the upper edge of the planet radius valley for its orbital period, confirming that it has likely retained a volatile atmosphere and that the "asteroseismic radius valley" remains devoid of planets. Our analysis favors a low eccentricity for pi Men c (<0.1 at 68% confidence), suggesting efficient tidal dissipation (Q/k <~ 2400) if it formed via high-eccentricity migration. Combined, these early results demonstrate the strong potential of TESS 20-second cadence data for stellar astrophysics and exoplanet science. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.09109v2-abstract-full').style.display = 'none'; document.getElementById('2108.09109v2-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 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 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">17 pages (excluding references), 13 figures, 6 tables; accepted for publication in AJ. Data and scripts to reproduce results are archived at https://zenodo.org/record/5555456</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.13583">arXiv:2107.13583</a> <span> [<a href="https://arxiv.org/pdf/2107.13583">pdf</a>, <a href="https://arxiv.org/format/2107.13583">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="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/10.3847/1538-3881/ac1b31">10.3847/1538-3881/ac1b31 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Asteroseismology of iota Draconis and Discovery of an Additional Long-Period Companion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Hill%2C+M+L">Michelle L. Hill</a>, <a href="/search/?searchtype=author&query=Kane%2C+S+R">Stephen R. Kane</a>, <a href="/search/?searchtype=author&query=Campante%2C+T+L">Tiago L. Campante</a>, <a href="/search/?searchtype=author&query=Li%2C+Z">Zhexing Li</a>, <a href="/search/?searchtype=author&query=Dalba%2C+P+A">Paul A. Dalba</a>, <a href="/search/?searchtype=author&query=Brandt%2C+T+D">Timothy D. Brandt</a>, <a href="/search/?searchtype=author&query=White%2C+T+R">Timothy R. White</a>, <a href="/search/?searchtype=author&query=Pope%2C+B+J+S">Benjamin J. S. Pope</a>, <a href="/search/?searchtype=author&query=Stassun%2C+K+G">Keivan G. Stassun</a>, <a href="/search/?searchtype=author&query=Fulton%2C+B+J">Benjamin J. Fulton</a>, <a href="/search/?searchtype=author&query=Corsaro%2C+E">Enrico Corsaro</a>, <a href="/search/?searchtype=author&query=Li%2C+T">Tanda Li</a>, <a href="/search/?searchtype=author&query=Ong%2C+J+M+J">J. M. Joel Ong</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Bossini%2C+D">Diego Bossini</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">Margarida S. Cunha</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">Rafael A. Garcia</a>, <a href="/search/?searchtype=author&query=Breton%2C+S+N">Sylvain N. Breton</a>, <a href="/search/?searchtype=author&query=Hon%2C+M">Marc Hon</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Jiang%2C+C">Chen Jiang</a>, <a href="/search/?searchtype=author&query=Kayhan%2C+C">Cenk Kayhan</a>, <a href="/search/?searchtype=author&query=Kuszlewicz%2C+J+S">James S. Kuszlewicz</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="2107.13583v1-abstract-short" style="display: inline;"> Giant stars as known exoplanet hosts are relatively rare due to the potential challenges in acquiring precision radial velocities and the small predicted transit depths. However, these giant host stars are also some of the brightest in the sky and so enable high signal-to-noise follow-up measurements. Here we report on new observations of the bright (V ~ 3.3) giant star $喂$ Draconis ($喂$ Dra), kno… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.13583v1-abstract-full').style.display = 'inline'; document.getElementById('2107.13583v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.13583v1-abstract-full" style="display: none;"> Giant stars as known exoplanet hosts are relatively rare due to the potential challenges in acquiring precision radial velocities and the small predicted transit depths. However, these giant host stars are also some of the brightest in the sky and so enable high signal-to-noise follow-up measurements. Here we report on new observations of the bright (V ~ 3.3) giant star $喂$ Draconis ($喂$ Dra), known to host a planet in a highly eccentric ~511 day period orbit. TESS observations of the star over 137 days reveal asteroseismic signatures, allowing us to constrain the stellar radius, mass, and age to ~2%, ~6%, and ~28%, respectively. We present the results of continued radial velocity monitoring of the star using the Automated Planet Finder over several orbits of the planet. We provide more precise planet parameters of the known planet and, through the combination of our radial velocity measurements with Hipparcos and Gaia astrometry, we discover an additional long-period companion with an orbital period of ~$68^{+60}_{-36}$ years. Mass predictions from our analysis place this sub-stellar companion on the border of the planet and brown dwarf regimes. The bright nature of the star combined with the revised orbital architecture of the system provides an opportunity to study planetary orbital dynamics that evolve as the star moves into the giant phase of its evolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.13583v1-abstract-full').style.display = 'none'; document.getElementById('2107.13583v1-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 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">20 pages, 11 Figures, Accepted for publication in the Astronomical 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/2106.08341">arXiv:2106.08341</a> <span> [<a href="https://arxiv.org/pdf/2106.08341">pdf</a>, <a href="https://arxiv.org/format/2106.08341">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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/10.3847/1538-3881/ac09f1">10.3847/1538-3881/ac09f1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> TESS Data for Asteroseismology: Photometry </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Handberg%2C+R">Rasmus Handberg</a>, <a href="/search/?searchtype=author&query=Lund%2C+M+N">Mikkel N. Lund</a>, <a href="/search/?searchtype=author&query=White%2C+T+R">Timothy R. White</a>, <a href="/search/?searchtype=author&query=Hall%2C+O+J">Oliver J. Hall</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Pope%2C+B+J+S">Benjamin J. S. Pope</a>, <a href="/search/?searchtype=author&query=Hansen%2C+J+S">Jonas S. Hansen</a>, <a href="/search/?searchtype=author&query=von+Essen%2C+C">Carolina von Essen</a>, <a href="/search/?searchtype=author&query=Carboneau%2C+L">Lindsey Carboneau</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Vanderspek%2C+R+K">Roland K. Vanderspek</a>, <a href="/search/?searchtype=author&query=Fausnaug%2C+M+M">Michael M. Fausnaug</a>, <a href="/search/?searchtype=author&query=Tenenbaum%2C+P">Peter Tenenbaum</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J+M">Jon M. Jenkins</a>, <a href="/search/?searchtype=author&query=Collaboration%2C+t+T">the T'DA Collaboration</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="2106.08341v1-abstract-short" style="display: inline;"> Over the last two decades, asteroseismology has increasingly proven to be the observational tool of choice for the study of stellar physics, aided by the high quality of data available from space-based missions such as CoRoT, Kepler, K2 and TESS. TESS in particular will produce more than an order of magnitude more such data than has ever been available before. While the standard TESS mission pro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.08341v1-abstract-full').style.display = 'inline'; document.getElementById('2106.08341v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.08341v1-abstract-full" style="display: none;"> Over the last two decades, asteroseismology has increasingly proven to be the observational tool of choice for the study of stellar physics, aided by the high quality of data available from space-based missions such as CoRoT, Kepler, K2 and TESS. TESS in particular will produce more than an order of magnitude more such data than has ever been available before. While the standard TESS mission products include light curves from 120-sec observations suitable for both exoplanet and asteroseismic studies, they do not include light curves for the vastly larger number of targets observed by the mission at a longer 1800-sec cadence in Full Frame Images (FFIs). To address this lack, the TESS Data for Asteroseismology (T'DA) group under the TESS Asteroseismic Science Consortium (TASC), has constructed an open-source pipeline focused on producing light curves for all stars observed by TESS at all cadences, currently including stars down to a TESS magnitude of 15. The pipeline includes target identification, background estimation and removal, correction of FFI timestamps, and a range of potential photometric extraction methodologies, though aperture photometry is currently the default approach. For the brightest targets, we transparently apply a halo photometry algorithm to construct a calibrated light curve from unsaturated pixels in the image. In this paper, we describe in detail the algorithms, functionality, and products of this pipeline, and summarize the noise metrics for the light curves. Companion papers will address the removal of systematic noise sources from our light curves, and a stellar variability classification from these. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.08341v1-abstract-full').style.display = 'none'; document.getElementById('2106.08341v1-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 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">27 pages, 14 figures, Accepted for publication in The Astronomical 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/2105.13274">arXiv:2105.13274</a> <span> [<a href="https://arxiv.org/pdf/2105.13274">pdf</a>, <a href="https://arxiv.org/ps/2105.13274">ps</a>, <a href="https://arxiv.org/format/2105.13274">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/stab1578">10.1093/mnras/stab1578 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> TESS Cycle 1 observations of roAp stars with 2-min cadence data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Holdsworth%2C+D+L">D. L. Holdsworth</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">M. S. Cunha</a>, <a href="/search/?searchtype=author&query=Kurtz%2C+D+W">D. W. Kurtz</a>, <a href="/search/?searchtype=author&query=Antoci%2C+V">V. Antoci</a>, <a href="/search/?searchtype=author&query=Hey%2C+D+R">D. R. Hey</a>, <a href="/search/?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/?searchtype=author&query=Kobzar%2C+O">O. Kobzar</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Kochukhov%2C+O">O. Kochukhov</a>, <a href="/search/?searchtype=author&query=Niemczura%2C+E">E. Niemczura</a>, <a href="/search/?searchtype=author&query=Ozuyar%2C+D">D. Ozuyar</a>, <a href="/search/?searchtype=author&query=Shi%2C+F">F. Shi</a>, <a href="/search/?searchtype=author&query=Szab%C3%B3%2C+R">R. Szab贸</a>, <a href="/search/?searchtype=author&query=Samadi-Ghadim%2C+A">A. Samadi-Ghadim</a>, <a href="/search/?searchtype=author&query=Bogn%C3%A1r%2C+Z">Zs. Bogn谩r</a>, <a href="/search/?searchtype=author&query=Fox-Machado%2C+L">L. Fox-Machado</a>, <a href="/search/?searchtype=author&query=Khalack%2C+V">V. Khalack</a>, <a href="/search/?searchtype=author&query=Lares-Martiz%2C+M">M. Lares-Martiz</a>, <a href="/search/?searchtype=author&query=Lovekin%2C+C+C">C. C. Lovekin</a>, <a href="/search/?searchtype=author&query=Miko%C5%82ajczyk%2C+P">P. Miko艂ajczyk</a>, <a href="/search/?searchtype=author&query=Mkrtichian%2C+D">D. Mkrtichian</a>, <a href="/search/?searchtype=author&query=Pascual-Granado%2C+J">J. Pascual-Granado</a>, <a href="/search/?searchtype=author&query=Paunzen%2C+E">E. Paunzen</a>, <a href="/search/?searchtype=author&query=Richey-Yowell%2C+T">T. Richey-Yowell</a>, <a href="/search/?searchtype=author&query=S%C3%B3dor%2C+%C3%81">脕. S贸dor</a> , et al. (19 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="2105.13274v1-abstract-short" style="display: inline;"> We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS) during its Cycle 1 observations. We identify 12 new roAp stars. Amongst these stars we discover the roAp star with the longest pulsation period, another with the shortest rotation period, and six with multiperiodic vari… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.13274v1-abstract-full').style.display = 'inline'; document.getElementById('2105.13274v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.13274v1-abstract-full" style="display: none;"> We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS) during its Cycle 1 observations. We identify 12 new roAp stars. Amongst these stars we discover the roAp star with the longest pulsation period, another with the shortest rotation period, and six with multiperiodic variability. In addition to these new roAp stars, we present an analysis of 44 known roAp stars observed by TESS during Cycle 1, providing the first high-precision and homogeneous sample of a significant fraction of the known roAp stars. The TESS observations have shown that almost 60 per cent (33) of our sample of stars are multiperiodic, providing excellent cases to test models of roAp pulsations, and from which the most rewarding asteroseismic results can be gleaned. We report four cases of the occurrence of rotationally split frequency multiplets that imply different mode geometries for the same degree modes in the same star. This provides a conundrum in applying the oblique pulsator model to the roAp stars. Finally, we report the discovery of non-linear mode interactions in $伪$ Cir (TIC 402546736, HD 128898) around the harmonic of the principal mode -- this is only the second case of such a phenomenon. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.13274v1-abstract-full').style.display = 'none'; document.getElementById('2105.13274v1-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 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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. 38 Pages, 50 Figures, 1 Table, 2 Appendices</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2005.00272">arXiv:2005.00272</a> <span> [<a href="https://arxiv.org/pdf/2005.00272">pdf</a>, <a href="https://arxiv.org/format/2005.00272">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/ab8f29">10.3847/1538-4357/ab8f29 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> TESS Asteroseismic Analysis of the Known Exoplanet Host Star HD 222076 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Jiang%2C+C">Chen Jiang</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Stassun%2C+K+G">Keivan G. Stassun</a>, <a href="/search/?searchtype=author&query=Veras%2C+D">Dimitri Veras</a>, <a href="/search/?searchtype=author&query=Corsaro%2C+E">Enrico Corsaro</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Miko%C5%82ajczyk%2C+P">Przemys艂aw Miko艂ajczyk</a>, <a href="/search/?searchtype=author&query=Qian-sheng"> Qian-sheng</a>, <a href="/search/?searchtype=author&query=Zhang"> Zhang</a>, <a href="/search/?searchtype=author&query=Jian-wen"> Jian-wen</a>, <a href="/search/?searchtype=author&query=Ou"> Ou</a>, <a href="/search/?searchtype=author&query=Campante%2C+T+L">Tiago L. Campante</a>, <a href="/search/?searchtype=author&query=Rodrigues%2C+T+S">Tha铆se S. Rodrigues</a>, <a href="/search/?searchtype=author&query=Nsamba%2C+B">Benard Nsamba</a>, <a href="/search/?searchtype=author&query=Bossini%2C+D">Diego Bossini</a>, <a href="/search/?searchtype=author&query=Kane%2C+S+R">Stephen R. Kane</a>, <a href="/search/?searchtype=author&query=Ong%2C+J+M+J">Jia Mian Joel Ong</a>, <a href="/search/?searchtype=author&query=Y%C4%B1ld%C4%B1z%2C+M">Mutlu Y谋ld谋z</a>, <a href="/search/?searchtype=author&query=Orhan%2C+Z+%C3%87">Zeynep 脟eiik Orhan</a>, <a href="/search/?searchtype=author&query=%C3%96rtel%2C+S">Sibel 脰rtel</a>, <a href="/search/?searchtype=author&query=Wu%2C+T">Tao Wu</a>, <a href="/search/?searchtype=author&query=Zhang%2C+X">Xinyi Zhang</a>, <a href="/search/?searchtype=author&query=Li%2C+T">Tanda Li</a>, <a href="/search/?searchtype=author&query=Basu%2C+S">Sarbani Basu</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">Margarida S. Cunha</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="2005.00272v1-abstract-short" style="display: inline;"> The Transiting Exoplanet Survey Satellite (TESS) is an all-sky survey mission aiming to search for exoplanets that transit bright stars. The high-quality photometric data of TESS are excellent for the asteroseismic study of solar-like stars. In this work, we present an asteroseismic analysis of the red-giant star HD~222076 hosting a long-period (2.4 yr) giant planet discovered through radial veloc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2005.00272v1-abstract-full').style.display = 'inline'; document.getElementById('2005.00272v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2005.00272v1-abstract-full" style="display: none;"> The Transiting Exoplanet Survey Satellite (TESS) is an all-sky survey mission aiming to search for exoplanets that transit bright stars. The high-quality photometric data of TESS are excellent for the asteroseismic study of solar-like stars. In this work, we present an asteroseismic analysis of the red-giant star HD~222076 hosting a long-period (2.4 yr) giant planet discovered through radial velocities. Solar-like oscillations of HD~222076 are detected around $203 \, 渭$Hz by TESS for the first time. Asteroseismic modeling, using global asteroseismic parameters as input, yields a determination of the stellar mass ($M_\star = 1.12 \pm 0.12\, M_\odot$), radius ($R_\star = 4.34 \pm 0.21\,R_\odot$), and age ($7.4 \pm 2.7\,$Gyr), with precisions greatly improved from previous studies. The period spacing of the dipolar mixed modes extracted from the observed power spectrum reveals that the star is on the red-giant branch burning hydrogen in a shell surrounding the core. We find that the planet will not escape the tidal pull of the star and be engulfed into it within about $800\,$Myr, before the tip of the red-giant branch is reached. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2005.00272v1-abstract-full').style.display = 'none'; document.getElementById('2005.00272v1-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 May, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">18 pages, 6 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/2001.07345">arXiv:2001.07345</a> <span> [<a href="https://arxiv.org/pdf/2001.07345">pdf</a>, <a href="https://arxiv.org/format/2001.07345">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="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/staa3960">10.1093/mnras/staa3960 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Addison%2C+B+C">Brett C. Addison</a>, <a href="/search/?searchtype=author&query=Wright%2C+D+J">Duncan J. Wright</a>, <a href="/search/?searchtype=author&query=Nicholson%2C+B+A">Belinda A. Nicholson</a>, <a href="/search/?searchtype=author&query=Cale%2C+B">Bryson Cale</a>, <a href="/search/?searchtype=author&query=Mocnik%2C+T">Teo Mocnik</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Plavchan%2C+P">Peter Plavchan</a>, <a href="/search/?searchtype=author&query=Wittenmyer%2C+R+A">Robert A. Wittenmyer</a>, <a href="/search/?searchtype=author&query=Vanderburg%2C+A">Andrew Vanderburg</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Chontos%2C+A">Ashley Chontos</a>, <a href="/search/?searchtype=author&query=Clark%2C+J+T">Jake T. Clark</a>, <a href="/search/?searchtype=author&query=Eastman%2C+J+D">Jason D. Eastman</a>, <a href="/search/?searchtype=author&query=Ziegler%2C+C">Carl Ziegler</a>, <a href="/search/?searchtype=author&query=Brahm%2C+R">Rafael Brahm</a>, <a href="/search/?searchtype=author&query=Carter%2C+B+D">Bradley D. Carter</a>, <a href="/search/?searchtype=author&query=Clerte%2C+M">Mathieu Clerte</a>, <a href="/search/?searchtype=author&query=Espinoza%2C+N">N茅stor Espinoza</a>, <a href="/search/?searchtype=author&query=Horner%2C+J">Jonathan Horner</a>, <a href="/search/?searchtype=author&query=Bentley%2C+J">John Bentley</a>, <a href="/search/?searchtype=author&query=Jord%C3%A1n%2C+A">Andr茅s Jord谩n</a>, <a href="/search/?searchtype=author&query=Kane%2C+S+R">Stephen R. Kane</a>, <a href="/search/?searchtype=author&query=Kielkopf%2C+J+F">John F. Kielkopf</a>, <a href="/search/?searchtype=author&query=Laychock%2C+E">Emilie Laychock</a>, <a href="/search/?searchtype=author&query=Mengel%2C+M+W">Matthew W. Mengel</a> , et al. (69 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="2001.07345v2-abstract-short" style="display: inline;"> We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial velocity observations. An analysis of the TESS photometry, the Minerva-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar osci… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.07345v2-abstract-full').style.display = 'inline'; document.getElementById('2001.07345v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.07345v2-abstract-full" style="display: none;"> We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial velocity observations. An analysis of the TESS photometry, the Minerva-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar oscillations reveals that TOI-257b has a mass of $M_P=0.138\pm0.023$\,$\rm{M_J}$ ($43.9\pm7.3$\,$M_{\rm \oplus}$), a radius of $R_P=0.639\pm0.013$\,$\rm{R_J}$ ($7.16\pm0.15$\,$R_{\rm \oplus}$), bulk density of $0.65^{+0.12}_{-0.11}$ (cgs), and period $18.38818^{+0.00085}_{-0.00084}$\,$\rm{days}$. TOI-257b orbits a bright ($\mathrm{V}=7.612$\,mag) somewhat evolved late F-type star with $M_*=1.390\pm0.046$\,$\rm{M_{\odot}}$, $R_*=1.888\pm0.033$\,$\rm{R_{\odot}}$, $T_{\rm eff}=6075\pm90$\,$\rm{K}$, and $v\sin{i}=11.3\pm0.5$\,km\,s$^{-1}$. Additionally, we find hints for a second non-transiting sub-Saturn mass planet on a $\sim71$\,day orbit using the radial velocity data. This system joins the ranks of a small number of exoplanet host stars ($\sim100$) that have been characterized with asteroseismology. Warm sub-Saturns are rare in the known sample of exoplanets, and thus the discovery of TOI-257b is important in the context of future work studying the formation and migration history of similar planetary systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.07345v2-abstract-full').style.display = 'none'; document.getElementById('2001.07345v2-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> 11 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">24 pages, 20 figures, 6 tables. Published 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/2001.04653">arXiv:2001.04653</a> <span> [<a href="https://arxiv.org/pdf/2001.04653">pdf</a>, <a href="https://arxiv.org/format/2001.04653">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/10.1038/s41550-019-0975-9">10.1038/s41550-019-0975-9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Age dating of an early Milky Way merger via asteroseismology of the naked-eye star $谓$ Indi </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Serenelli%2C+A+M">Aldo M. Serenelli</a>, <a href="/search/?searchtype=author&query=Miglio%2C+A">Andrea Miglio</a>, <a href="/search/?searchtype=author&query=Morel%2C+T">Thierry Morel</a>, <a href="/search/?searchtype=author&query=Mackereth%2C+J+T">J. Ted Mackereth</a>, <a href="/search/?searchtype=author&query=Vincenzo%2C+F">Fiorenzo Vincenzo</a>, <a href="/search/?searchtype=author&query=Basu%2C+H+K+S">Hans Kjeldsen Sarbani Basu</a>, <a href="/search/?searchtype=author&query=Ball%2C+W+H">Warrick H. Ball</a>, <a href="/search/?searchtype=author&query=Stokholm%2C+A">Amalie Stokholm</a>, <a href="/search/?searchtype=author&query=Verma%2C+K">Kuldeep Verma</a>, <a href="/search/?searchtype=author&query=Mosumgaard%2C+J+R">Jakob R酶rsted Mosumgaard</a>, <a href="/search/?searchtype=author&query=Aguirre%2C+V+S">Victor Silva Aguirre</a>, <a href="/search/?searchtype=author&query=Mazumdar%2C+A">Anwesh Mazumdar</a>, <a href="/search/?searchtype=author&query=Ranadive%2C+P">Pritesh Ranadive</a>, <a href="/search/?searchtype=author&query=Antia%2C+H+M">H. M. Antia</a>, <a href="/search/?searchtype=author&query=Lebreton%2C+Y">Yveline Lebreton</a>, <a href="/search/?searchtype=author&query=Ong%2C+J">Joel Ong</a>, <a href="/search/?searchtype=author&query=Appourchaux%2C+T">Thierry Appourchaux</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J酶rgen Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Creevey%2C+O">Orlagh Creevey</a>, <a href="/search/?searchtype=author&query=Garc%C3%ADa%2C+R+A">Rafael A. Garc铆a</a>, <a href="/search/?searchtype=author&query=Handberg%2C+R">Rasmus Handberg</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Kawaler%2C+S+D">Steven D. Kawaler</a> , et al. (59 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="2001.04653v1-abstract-short" style="display: inline;"> Over the course of its history, the Milky Way has ingested multiple smaller satellite galaxies. While these accreted stellar populations can be forensically identified as kinematically distinct structures within the Galaxy, it is difficult in general to precisely date the age at which any one merger occurred. Recent results have revealed a population of stars that were accreted via the collision o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.04653v1-abstract-full').style.display = 'inline'; document.getElementById('2001.04653v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.04653v1-abstract-full" style="display: none;"> Over the course of its history, the Milky Way has ingested multiple smaller satellite galaxies. While these accreted stellar populations can be forensically identified as kinematically distinct structures within the Galaxy, it is difficult in general to precisely date the age at which any one merger occurred. Recent results have revealed a population of stars that were accreted via the collision of a dwarf galaxy, called \textit{Gaia}-Enceladus, leading to a substantial pollution of the chemical and dynamical properties of the Milky Way. Here, we identify the very bright, naked-eye star $谓$\,Indi as a probe of the age of the early in situ population of the Galaxy. We combine asteroseismic, spectroscopic, astrometric, and kinematic observations to show that this metal-poor, alpha-element-rich star was an indigenous member of the halo, and we measure its age to be $11.0 \pm 0.7$ (stat) $\pm 0.8$ (sys)$\,\rm Gyr$. The star bears hallmarks consistent with it having been kinematically heated by the \textit{Gaia}-Enceladus collision. Its age implies that the earliest the merger could have begun was 11.6 and 13.2 Gyr ago at 68 and 95% confidence, respectively. Input from computations based on hierarchical cosmological models tightens (i.e. reduces) slightly the above limits. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.04653v1-abstract-full').style.display = 'none'; document.getElementById('2001.04653v1-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> 14 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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 as a Letter in Nature Astronomy (26 pages, 7 figures, including main article and methods section)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1909.12018">arXiv:1909.12018</a> <span> [<a href="https://arxiv.org/pdf/1909.12018">pdf</a>, <a href="https://arxiv.org/format/1909.12018">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/stz2787">10.1093/mnras/stz2787 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The first view of $未$ Scuti and $纬$ Doradus stars with the TESS mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Antoci%2C+V">V. Antoci</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">M. S. Cunha</a>, <a href="/search/?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/?searchtype=author&query=Murphy%2C+S+J">S. J. Murphy</a>, <a href="/search/?searchtype=author&query=Kurtz%2C+D+W">D. W. Kurtz</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Borre%2C+C+C">C. C. Borre</a>, <a href="/search/?searchtype=author&query=Christophe%2C+S">S. Christophe</a>, <a href="/search/?searchtype=author&query=Daszy%C5%84ska-Daszkiewicz%2C+J">J. Daszy艅ska-Daszkiewicz</a>, <a href="/search/?searchtype=author&query=Fox-Machado%2C+L">L. Fox-Machado</a>, <a href="/search/?searchtype=author&query=Hern%C3%A1ndez%2C+A+G">A. Garc铆a Hern谩ndez</a>, <a href="/search/?searchtype=author&query=Ghasemi%2C+H">H. Ghasemi</a>, <a href="/search/?searchtype=author&query=Handberg%2C+R">R. Handberg</a>, <a href="/search/?searchtype=author&query=Hansen%2C+H">H. Hansen</a>, <a href="/search/?searchtype=author&query=Hasanzadeh%2C+A">A. Hasanzadeh</a>, <a href="/search/?searchtype=author&query=Houdek%2C+G">G. Houdek</a>, <a href="/search/?searchtype=author&query=Johnston%2C+C">C. Johnston</a>, <a href="/search/?searchtype=author&query=Justesen%2C+A+B">A. B. Justesen</a>, <a href="/search/?searchtype=author&query=Alicavus%2C+F+K">F. Kahraman Alicavus</a>, <a href="/search/?searchtype=author&query=Kotysz%2C+K">K. Kotysz</a>, <a href="/search/?searchtype=author&query=Latham%2C+D">D. Latham</a>, <a href="/search/?searchtype=author&query=Matthews%2C+J+M">J. M. Matthews</a>, <a href="/search/?searchtype=author&query=M%C3%B8nster%2C+J">J. M酶nster</a>, <a href="/search/?searchtype=author&query=Niemczura%2C+E">E. Niemczura</a>, <a href="/search/?searchtype=author&query=Paunzen%2C+E">E. Paunzen</a> , et al. (41 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="1909.12018v1-abstract-short" style="display: inline;"> We present the first asteroseismic results for $未$ Scuti and $纬$ Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilise the 2-min cadence TESS data for a sample of 117 stars to classify their behaviour regarding variability and place them in the Hertzsprung-Russell diagram using Gaia DR2 data. Included within our sample are the eponymous members of two pulsator classes, $纬$ Dora… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.12018v1-abstract-full').style.display = 'inline'; document.getElementById('1909.12018v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1909.12018v1-abstract-full" style="display: none;"> We present the first asteroseismic results for $未$ Scuti and $纬$ Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilise the 2-min cadence TESS data for a sample of 117 stars to classify their behaviour regarding variability and place them in the Hertzsprung-Russell diagram using Gaia DR2 data. Included within our sample are the eponymous members of two pulsator classes, $纬$ Doradus and SX Phoenicis. Our sample of pulsating intermediate-mass stars observed by TESS also allows us to confront theoretical models of pulsation driving in the classical instability strip for the first time and show that mixing processes in the outer envelope play an important role. We derive an empirical estimate of 74% for the relative amplitude suppression factor as a result of the redder TESS passband compared to the Kepler mission using a pulsating eclipsing binary system. Furthermore, our sample contains many high-frequency pulsators, allowing us to probe the frequency variability of hot young $未$ Scuti stars, which were lacking in the Kepler mission data set, and identify promising targets for future asteroseismic modelling. The TESS data also allow us to refine the stellar parameters of SX Phoenicis, which is believed to be a blue straggler. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.12018v1-abstract-full').style.display = 'none'; document.getElementById('1909.12018v1-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 September, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2019. </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">33 pages (incl. appendix), accepted for publications 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/1906.01111">arXiv:1906.01111</a> <span> [<a href="https://arxiv.org/pdf/1906.01111">pdf</a>, <a href="https://arxiv.org/format/1906.01111">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/stz1332">10.1093/mnras/stz1332 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Rotation and pulsation in Ap stars: first light results from TESS sectors 1 and 2 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cunha%2C+M+S">M. S. Cunha</a>, <a href="/search/?searchtype=author&query=Antoci%2C+V">V. Antoci</a>, <a href="/search/?searchtype=author&query=Holdsworth%2C+D+L">D. L. Holdsworth</a>, <a href="/search/?searchtype=author&query=Kurtz%2C+D+W">D. W. Kurtz</a>, <a href="/search/?searchtype=author&query=Balona%2C+L+A">L. A. Balona</a>, <a href="/search/?searchtype=author&query=Bogn%C3%A1r%2C+Z">Zs. Bogn谩r</a>, <a href="/search/?searchtype=author&query=Bowman%2C+D+M">D. M. Bowman</a>, <a href="/search/?searchtype=author&query=Guo%2C+Z">Z. Guo</a>, <a href="/search/?searchtype=author&query=Ko%C5%82aczek-Szyma%C5%84ski%2C+P+A">P. A. Ko艂aczek-Szyma艅ski</a>, <a href="/search/?searchtype=author&query=Lares-Martiz%2C+M">M. Lares-Martiz</a>, <a href="/search/?searchtype=author&query=Paunzen%2C+E">E. Paunzen</a>, <a href="/search/?searchtype=author&query=Skarka%2C+M">M. Skarka</a>, <a href="/search/?searchtype=author&query=Smalley%2C+B">B. Smalley</a>, <a href="/search/?searchtype=author&query=S%C3%B3dor%2C+%C3%81">脕. S贸dor</a>, <a href="/search/?searchtype=author&query=Kochukhov%2C+O">O. Kochukhov</a>, <a href="/search/?searchtype=author&query=Pepper%2C+J">J. Pepper</a>, <a href="/search/?searchtype=author&query=Richey-Yowell%2C+T">T. Richey-Yowell</a>, <a href="/search/?searchtype=author&query=Ricker%2C+G+R">G. R. Ricker</a>, <a href="/search/?searchtype=author&query=Seager%2C+S">S. Seager</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Fox-Machado%2C+L">L. Fox-Machado</a>, <a href="/search/?searchtype=author&query=Hasanzadeh%2C+A">A. Hasanzadeh</a>, <a href="/search/?searchtype=author&query=Niemczura%2C+E">E. Niemczura</a>, <a href="/search/?searchtype=author&query=Quitral-Manosalva%2C+P">P. Quitral-Manosalva</a>, <a href="/search/?searchtype=author&query=Monteiro%2C+M+J+P+F+G">M. J. P. F. G. Monteiro</a> , et al. (14 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="1906.01111v1-abstract-short" style="display: inline;"> We present the first results from the Transiting Exoplanet Survey Satellite (TESS) on the rotational and pulsational variability of magnetic chemically peculiar A-type stars. We analyse TESS 2-min cadence data from sectors 1 and 2 on a sample of 83 stars. Five new rapidly oscillating Ap (roAp) stars are announced. One of these pulsates with periods around 4.7 min, making it the shortest period roA… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.01111v1-abstract-full').style.display = 'inline'; document.getElementById('1906.01111v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1906.01111v1-abstract-full" style="display: none;"> We present the first results from the Transiting Exoplanet Survey Satellite (TESS) on the rotational and pulsational variability of magnetic chemically peculiar A-type stars. We analyse TESS 2-min cadence data from sectors 1 and 2 on a sample of 83 stars. Five new rapidly oscillating Ap (roAp) stars are announced. One of these pulsates with periods around 4.7 min, making it the shortest period roAp star known to date. Four out of the five new roAp stars are multiperiodic. Three of these, and the singly-periodic one show the presence of rotational mode splitting. Individual frequencies are provided in all cases. In addition, seven previously known roAp stars are analysed. Additional modes of oscillation are found in some stars, while in others we are able to distinguish the true pulsations from possible aliases present in the ground-based data. We find that the pulsation amplitude in the TESS filter is typically a factor 6 smaller than that in the $B$ filter which is usually used for ground-based observations. For four roAp stars we set constraints on the inclination angle and magnetic obliquity, through the application of the oblique pulsator model. We also confirm the absence of roAp-type pulsations down to amplitude limits of 6 and 13 micromag, respectively, in two of the best characterised non-oscillating Ap (noAp) stars. We announce 27 new rotational variables along with their rotation periods, and provide different rotation periods for seven other stars. Finally, we discuss how these results challenge state-of-the-art pulsation models for roAp stars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.01111v1-abstract-full').style.display = 'none'; document.getElementById('1906.01111v1-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 June, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2019. </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">29 pages, accepted for publication in the 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/1902.08312">arXiv:1902.08312</a> <span> [<a href="https://arxiv.org/pdf/1902.08312">pdf</a>, <a href="https://arxiv.org/ps/1902.08312">ps</a>, <a href="https://arxiv.org/format/1902.08312">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/10.3847/2041-8213/ab095f">10.3847/2041-8213/ab095f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Asteroseismology of massive stars with the TESS mission: the runaway Beta Cep pulsator PHL 346 = HN Aqr </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Handler%2C+G">Gerald Handler</a>, <a href="/search/?searchtype=author&query=Pigulski%2C+A">Andrzej Pigulski</a>, <a href="/search/?searchtype=author&query=Daszy%C5%84ska-Daszkiewicz%2C+J">Jadwiga Daszy艅ska-Daszkiewicz</a>, <a href="/search/?searchtype=author&query=Irrgang%2C+A">Andreas Irrgang</a>, <a href="/search/?searchtype=author&query=Kilkenny%2C+D">David Kilkenny</a>, <a href="/search/?searchtype=author&query=Guo%2C+Z">Zhao Guo</a>, <a href="/search/?searchtype=author&query=Przybilla%2C+N">Norbert Przybilla</a>, <a href="/search/?searchtype=author&query=Ali%C3%A7avu%C5%9F%2C+F+K">Filiz Kahraman Ali莽avu艧</a>, <a href="/search/?searchtype=author&query=Kallinger%2C+T">Thomas Kallinger</a>, <a href="/search/?searchtype=author&query=Pascual-Granado%2C+J">Javier Pascual-Granado</a>, <a href="/search/?searchtype=author&query=Niemczura%2C+E">Ewa Niemczura</a>, <a href="/search/?searchtype=author&query=R%C3%B3%C5%BCa%C5%84ski%2C+T">Tomasz R贸偶a艅ski</a>, <a href="/search/?searchtype=author&query=Chowdhury%2C+S">Sowgata Chowdhury</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Mirouh%2C+G+M">Giovanni M. Mirouh</a>, <a href="/search/?searchtype=author&query=Bowman%2C+D+M">Dominic M. Bowman</a>, <a href="/search/?searchtype=author&query=Johnston%2C+C">Cole Johnston</a>, <a href="/search/?searchtype=author&query=Pedersen%2C+M+G">May G. Pedersen</a>, <a href="/search/?searchtype=author&query=Sim%C3%B3n-Diaz%2C+S">Sergio Sim贸n-Diaz</a>, <a href="/search/?searchtype=author&query=Moravveji%2C+E">Ehsan Moravveji</a>, <a href="/search/?searchtype=author&query=Gazeas%2C+K">Kosmas Gazeas</a>, <a href="/search/?searchtype=author&query=De+Cat%2C+P">Peter De Cat</a>, <a href="/search/?searchtype=author&query=Vanderspek%2C+R+K">Roland K. Vanderspek</a>, <a href="/search/?searchtype=author&query=Ricker%2C+G+R">George R. Ricker</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="1902.08312v1-abstract-short" style="display: inline;"> We report an analysis of the first known Beta Cep pulsator observed by the TESS mission, the runaway star PHL 346 = HN Aqr. The star, previously known as a singly-periodic pulsator, has at least 34 oscillation modes excited, 12 of those in the g-mode domain and 22 p modes. Analysis of archival data implies that the amplitude and frequency of the dominant mode and the stellar radial velocity were v… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.08312v1-abstract-full').style.display = 'inline'; document.getElementById('1902.08312v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1902.08312v1-abstract-full" style="display: none;"> We report an analysis of the first known Beta Cep pulsator observed by the TESS mission, the runaway star PHL 346 = HN Aqr. The star, previously known as a singly-periodic pulsator, has at least 34 oscillation modes excited, 12 of those in the g-mode domain and 22 p modes. Analysis of archival data implies that the amplitude and frequency of the dominant mode and the stellar radial velocity were variable over time. A binary nature would be inconsistent with the inferred ejection velocity from the Galactic disc of 420 km/s, which is too large to be survivable by a runaway binary system. A kinematic analysis of the star results in an age constraint (23 +- 1 Myr) that can be imposed on asteroseismic modelling and that can be used to remove degeneracies in the modelling process. Our attempts to match the excitation of the observed frequency spectrum resulted in pulsation models that were too young. Hence, asteroseismic studies of runaway pulsators can become vital not only in tracing the evolutionary history of such objects, but to understand the interior structure of massive stars in general. TESS is now opening up these stars for detailed asteroseismic investigation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.08312v1-abstract-full').style.display = 'none'; document.getElementById('1902.08312v1-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 February, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2019. </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 ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1901.01643">arXiv:1901.01643</a> <span> [<a href="https://arxiv.org/pdf/1901.01643">pdf</a>, <a href="https://arxiv.org/format/1901.01643">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="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/10.3847/1538-3881/ab1488">10.3847/1538-3881/ab1488 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Hot Saturn Orbiting An Oscillating Late Subgiant Discovered by TESS </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Chontos%2C+A">Ashley Chontos</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">Hans Kjeldsen</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">Joergen Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Ball%2C+W">Warrick Ball</a>, <a href="/search/?searchtype=author&query=Brahm%2C+R">Rafael Brahm</a>, <a href="/search/?searchtype=author&query=Espinoza%2C+N">Nestor Espinoza</a>, <a href="/search/?searchtype=author&query=Henning%2C+T">Thomas Henning</a>, <a href="/search/?searchtype=author&query=Jordan%2C+A">Andres Jordan</a>, <a href="/search/?searchtype=author&query=Sarkis%2C+P">Paula Sarkis</a>, <a href="/search/?searchtype=author&query=Knudstrup%2C+E">Emil Knudstrup</a>, <a href="/search/?searchtype=author&query=Albrecht%2C+S">Simon Albrecht</a>, <a href="/search/?searchtype=author&query=Grundahl%2C+F">Frank Grundahl</a>, <a href="/search/?searchtype=author&query=Andersen%2C+M+F">Mads Fredslund Andersen</a>, <a href="/search/?searchtype=author&query=Palle%2C+P+L">Pere L. Palle</a>, <a href="/search/?searchtype=author&query=Crossfield%2C+I">Ian Crossfield</a>, <a href="/search/?searchtype=author&query=Fulton%2C+B">Benjamin Fulton</a>, <a href="/search/?searchtype=author&query=Howard%2C+A+W">Andrew W. Howard</a>, <a href="/search/?searchtype=author&query=Isaacson%2C+H+T">Howard T. Isaacson</a>, <a href="/search/?searchtype=author&query=Weiss%2C+L+M">Lauren M. Weiss</a>, <a href="/search/?searchtype=author&query=Handberg%2C+R">Rasmus Handberg</a>, <a href="/search/?searchtype=author&query=Lund%2C+M+N">Mikkel N. Lund</a>, <a href="/search/?searchtype=author&query=Serenelli%2C+A+M">Aldo M. Serenelli</a> , et al. (117 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="1901.01643v2-abstract-short" style="display: inline;"> We present the discovery of TOI-197.01, the first transiting planet identified by the Transiting Exoplanet Survey Satellite (TESS) for which asteroseismology of the host star is possible. TOI-197 (HIP116158) is a bright (V=8.2 mag), spectroscopically classified subgiant which oscillates with an average frequency of about 430 muHz and displays a clear signature of mixed modes. The oscillation ampli… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.01643v2-abstract-full').style.display = 'inline'; document.getElementById('1901.01643v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1901.01643v2-abstract-full" style="display: none;"> We present the discovery of TOI-197.01, the first transiting planet identified by the Transiting Exoplanet Survey Satellite (TESS) for which asteroseismology of the host star is possible. TOI-197 (HIP116158) is a bright (V=8.2 mag), spectroscopically classified subgiant which oscillates with an average frequency of about 430 muHz and displays a clear signature of mixed modes. The oscillation amplitude confirms that the redder TESS bandpass compared to Kepler has a small effect on the oscillations, supporting the expected yield of thousands of solar-like oscillators with TESS 2-minute cadence observations. Asteroseismic modeling yields a robust determination of the host star radius (2.943+/-0.064 Rsun), mass (1.212 +/- 0.074 Msun) and age (4.9+/-1.1 Gyr), and demonstrates that it has just started ascending the red-giant branch. Combining asteroseismology with transit modeling and radial-velocity observations, we show that the planet is a "hot Saturn" (9.17+/-0.33 Rearth) with an orbital period of ~14.3 days, irradiance of 343+/-24 Fearth, moderate mass (60.5 +/- 5.7 Mearth) and density (0.431+/-0.062 gcc). The properties of TOI-197.01 show that the host-star metallicity - planet mass correlation found in sub-Saturns (4-8 Rearth) does not extend to larger radii, indicating that planets in the transition between sub-Saturns and Jupiters follow a relatively narrow range of densities. With a density measured to ~15%, TOI-197.01 is one of the best characterized Saturn-sized planets to date, augmenting the small number of known transiting planets around evolved stars and demonstrating the power of TESS to characterize exoplanets and their host stars using asteroseismology. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.01643v2-abstract-full').style.display = 'none'; document.getElementById('1901.01643v2-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 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 January, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2019. </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">12 pages (excluding author list and references), 9 figures, 4 tables, accepted for publication in AJ. An electronic version of Table 3 is available as an ancillary file (sidebar on the right)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1804.05833">arXiv:1804.05833</a> <span> [<a href="https://arxiv.org/pdf/1804.05833">pdf</a>, <a href="https://arxiv.org/ps/1804.05833">ps</a>, <a href="https://arxiv.org/format/1804.05833">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/10.1017/S1743921318001230">10.1017/S1743921318001230 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Building a Large Solar Analog Sample Using K2 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</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="1804.05833v1-abstract-short" style="display: inline;"> We have begun a project aimed at providing a large consistent set of well-vetted solar analogs in order to address questions of stellar rotation, activity, dynamos, and gyrochronology. We make use of the K2 mission fields to obtain precise photometric time series, supplemented by ground-based photometric and spectroscopic data for promising candidates. From this data we will derive rotation period… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.05833v1-abstract-full').style.display = 'inline'; document.getElementById('1804.05833v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1804.05833v1-abstract-full" style="display: none;"> We have begun a project aimed at providing a large consistent set of well-vetted solar analogs in order to address questions of stellar rotation, activity, dynamos, and gyrochronology. We make use of the K2 mission fields to obtain precise photometric time series, supplemented by ground-based photometric and spectroscopic data for promising candidates. From this data we will derive rotation periods, spot coverages, and flare rates for a well-defined and well-calibrated sample of solar analogs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.05833v1-abstract-full').style.display = 'none'; document.getElementById('1804.05833v1-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> 14 April, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2018. </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">To appear in "Long-Term Datasets for the Understanding of Solar and Stellar Magnetic Cycles", Proc. IAU Symposium 340</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1511.09069">arXiv:1511.09069</a> <span> [<a href="https://arxiv.org/pdf/1511.09069">pdf</a>, <a href="https://arxiv.org/ps/1511.09069">ps</a>, <a href="https://arxiv.org/format/1511.09069">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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"> Serendipitous Science from the K2 Mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Carboneau%2C+L">Lindsey Carboneau</a>, <a href="/search/?searchtype=author&query=Hessler%2C+C">Carly Hessler</a>, <a href="/search/?searchtype=author&query=Lezcano%2C+A">Andy Lezcano</a>, <a href="/search/?searchtype=author&query=Preston%2C+H">Heather Preston</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="1511.09069v1-abstract-short" style="display: inline;"> The K2 mission is a repurposed use of the Kepler spacecraft to perform high-precision photometry of selected fields in the ecliptic. We have developed an aperture photometry pipeline for K2 data which performs dynamic automated aperture mask selection, background estimation and subtraction, and positional decorrelation to minimize the effects of spacecraft pointing jitter. We also identify seconda… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1511.09069v1-abstract-full').style.display = 'inline'; document.getElementById('1511.09069v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1511.09069v1-abstract-full" style="display: none;"> The K2 mission is a repurposed use of the Kepler spacecraft to perform high-precision photometry of selected fields in the ecliptic. We have developed an aperture photometry pipeline for K2 data which performs dynamic automated aperture mask selection, background estimation and subtraction, and positional decorrelation to minimize the effects of spacecraft pointing jitter. We also identify secondary targets in the K2 "postage stamps" and produce light curves for those targets as well. Pipeline results will be made available to the community. Here we describe our pipeline and the photometric precision we are capable of achieving with K2, and illustrate its utility with asteroseismic results from the serendipitous secondary targets. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1511.09069v1-abstract-full').style.display = 'none'; document.getElementById('1511.09069v1-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 November, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2015. </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, 9 figures To appear in IAU Focus Meeting 17, "Advances in Stellar Physics from Asteroseismology", ed. Piero Benvenuti</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1511.09068">arXiv:1511.09068</a> <span> [<a href="https://arxiv.org/pdf/1511.09068">pdf</a>, <a href="https://arxiv.org/ps/1511.09068">ps</a>, <a href="https://arxiv.org/format/1511.09068">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="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/10.1017/S1743921316000119">10.1017/S1743921316000119 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Stellar Wind -- Magnetosphere Interactions in Hot Jupiters </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</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="1511.09068v1-abstract-short" style="display: inline;"> One potential star-planet interaction mechanism for hot Jupiters involves planetary heating via currents set up by interactions between the stellar wind and planetary magnetosphere. Early modeling results indicate that such currents, which are analogous to the terrestrial global electric circuit (GEC), have the potential to provide sufficient heating to account for the additional radius inflation… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1511.09068v1-abstract-full').style.display = 'inline'; document.getElementById('1511.09068v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1511.09068v1-abstract-full" style="display: none;"> One potential star-planet interaction mechanism for hot Jupiters involves planetary heating via currents set up by interactions between the stellar wind and planetary magnetosphere. Early modeling results indicate that such currents, which are analogous to the terrestrial global electric circuit (GEC), have the potential to provide sufficient heating to account for the additional radius inflation seen in some hot Jupiters. Here we present a more detailed model of this phenomenon, exploring the scale of the effect, the circumstances under which it is likely to be significant, implications for the planetary magnetospheric structure, and observational signatures. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1511.09068v1-abstract-full').style.display = 'none'; document.getElementById('1511.09068v1-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 November, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2015. </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">3 pages, 4 figures To appear in IAU Symposium 320, "Solar and Stellar Flares and Their Effects on Planets", eds. A.G. Kosovichev, S.L. Hawley, and P. Heinzel</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1507.01827">arXiv:1507.01827</a> <span> [<a href="https://arxiv.org/pdf/1507.01827">pdf</a>, <a href="https://arxiv.org/ps/1507.01827">ps</a>, <a href="https://arxiv.org/format/1507.01827">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/10.1086/683103">10.1086/683103 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Asteroseismology of solar-type stars with K2 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=Lund%2C+M+N">M. N. Lund</a>, <a href="/search/?searchtype=author&query=Handberg%2C+R">R. Handberg</a>, <a href="/search/?searchtype=author&query=Basu%2C+S">S. Basu</a>, <a href="/search/?searchtype=author&query=Buchhave%2C+L+A">L. A. Buchhave</a>, <a href="/search/?searchtype=author&query=Campante%2C+T+L">T. L. Campante</a>, <a href="/search/?searchtype=author&query=Davies%2C+G+R">G. R. Davies</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">D. Huber</a>, <a href="/search/?searchtype=author&query=Latham%2C+D+W">D. W. Latham</a>, <a href="/search/?searchtype=author&query=Latham%2C+C+A">C. A. Latham</a>, <a href="/search/?searchtype=author&query=Serenelli%2C+A">A. Serenelli</a>, <a href="/search/?searchtype=author&query=Antia%2C+H+M">H. M. Antia</a>, <a href="/search/?searchtype=author&query=Appourchaux%2C+T">T. Appourchaux</a>, <a href="/search/?searchtype=author&query=Ball%2C+W+H">W. H. Ball</a>, <a href="/search/?searchtype=author&query=Benomar%2C+O">O. Benomar</a>, <a href="/search/?searchtype=author&query=Casagrande%2C+L">L. Casagrande</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Coelho%2C+H+R">H. R. Coelho</a>, <a href="/search/?searchtype=author&query=Creevey%2C+O+L">O. L. Creevey</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y">Y. Elsworth</a>, <a href="/search/?searchtype=author&query=Garc%2C+R+A">R. A. Garc</a>, <a href="/search/?searchtype=author&query=Gaulme%2C+P">P. Gaulme</a>, <a href="/search/?searchtype=author&query=Hekker%2C+S">S. Hekker</a>, <a href="/search/?searchtype=author&query=Kallinger%2C+T">T. Kallinger</a>, <a href="/search/?searchtype=author&query=Karoff%2C+C">C. Karoff</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="1507.01827v1-abstract-short" style="display: inline;"> We present the first detections by the NASA K2 Mission of oscillations in solar-type stars, using short-cadence data collected during K2 Campaign\,1 (C1). We understand the asteroseismic detection thresholds for C1-like levels of photometric performance, and we can detect oscillations in subgiants having dominant oscillation frequencies around $1000\,\rm 渭Hz$. Changes to the operation of the fine-… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1507.01827v1-abstract-full').style.display = 'inline'; document.getElementById('1507.01827v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1507.01827v1-abstract-full" style="display: none;"> We present the first detections by the NASA K2 Mission of oscillations in solar-type stars, using short-cadence data collected during K2 Campaign\,1 (C1). We understand the asteroseismic detection thresholds for C1-like levels of photometric performance, and we can detect oscillations in subgiants having dominant oscillation frequencies around $1000\,\rm 渭Hz$. Changes to the operation of the fine-guidance sensors are expected to give significant improvements in the high-frequency performance from C3 onwards. A reduction in the excess high-frequency noise by a factor of two-and-a-half in amplitude would bring main-sequence stars with dominant oscillation frequencies as high as ${\simeq 2500}\,\rm 渭Hz$ into play as potential asteroseismic targets for K2. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1507.01827v1-abstract-full').style.display = 'none'; document.getElementById('1507.01827v1-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 July, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2015. </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 PASP; 16 pages, 2 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/1506.08931">arXiv:1506.08931</a> <span> [<a href="https://arxiv.org/pdf/1506.08931">pdf</a>, <a href="https://arxiv.org/ps/1506.08931">ps</a>, <a href="https://arxiv.org/format/1506.08931">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/10.1088/2041-8205/809/1/L3">10.1088/2041-8205/809/1/L3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Oscillating red giants observed during Campaign 1 of the Kepler K2 mission: New prospects for galactic archaeology </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Stello%2C+D">D. Stello</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">D. Huber</a>, <a href="/search/?searchtype=author&query=Sharma%2C+S">S. Sharma</a>, <a href="/search/?searchtype=author&query=Johnson%2C+J">J. Johnson</a>, <a href="/search/?searchtype=author&query=Lund%2C+M+N">M. N. Lund</a>, <a href="/search/?searchtype=author&query=Handberg%2C+R">R. Handberg</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Aguirre%2C+V+S">V. Silva Aguirre</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=Miglio%2C+A">A. Miglio</a>, <a href="/search/?searchtype=author&query=Pinsonneault%2C+M">M. Pinsonneault</a>, <a href="/search/?searchtype=author&query=Basu%2C+S">S. Basu</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Bland-Hawthorn%2C+J">J. Bland-Hawthorn</a>, <a href="/search/?searchtype=author&query=Casagrande%2C+L">L. Casagrande</a>, <a href="/search/?searchtype=author&query=Davies%2C+G">G. Davies</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y">Y. Elsworth</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">R. A. Garcia</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">S. Mathur</a>, <a href="/search/?searchtype=author&query=Di+Mauro%2C+M+P">M. Pia Di Mauro</a>, <a href="/search/?searchtype=author&query=Mosser%2C+B">B. Mosser</a>, <a href="/search/?searchtype=author&query=Schneider%2C+D+P">D. P. Schneider</a>, <a href="/search/?searchtype=author&query=Serenelli%2C+A">A. Serenelli</a>, <a href="/search/?searchtype=author&query=Valentini%2C+M">M. Valentini</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="1506.08931v2-abstract-short" style="display: inline;"> NASA's re-purposed Kepler mission -- dubbed K2 -- has brought new scientific opportunities that were not anticipated for the original Kepler mission. One science goal that makes optimal use of K2's capabilities, in particular its 360-degree ecliptic field of view, is galactic archaeology -- the study of the evolution of the Galaxy from the fossil stellar record. The thrust of this research is to e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1506.08931v2-abstract-full').style.display = 'inline'; document.getElementById('1506.08931v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1506.08931v2-abstract-full" style="display: none;"> NASA's re-purposed Kepler mission -- dubbed K2 -- has brought new scientific opportunities that were not anticipated for the original Kepler mission. One science goal that makes optimal use of K2's capabilities, in particular its 360-degree ecliptic field of view, is galactic archaeology -- the study of the evolution of the Galaxy from the fossil stellar record. The thrust of this research is to exploit high-precision, time-resolved photometry from K2 in order to detect oscillations in red giant stars. This asteroseismic information can provide estimates of stellar radius (hence distance), mass and age of vast numbers of stars across the Galaxy. Here we present the initial analysis of a subset of red giants, observed towards the North Galactic Gap, during the mission's first full science campaign. We investigate the feasibility of using K2 data for detecting oscillations in red giants that span a range in apparent magnitude and evolutionary state (hence intrinsic luminosity). We demonstrate that oscillations are detectable for essentially all cool giants within the $\log g$ range $\sim 1.9-3.2$. Our detection is complete down to $\mathit{Kp}\sim 14.5$, which results in a seismic sample with little or no detection bias. This sample is ideally suited to stellar population studies that seek to investigate potential shortcomings of contemporary Galaxy models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1506.08931v2-abstract-full').style.display = 'none'; document.getElementById('1506.08931v2-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 July, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 June, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2015. </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, submitted to ApJL</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1402.3614">arXiv:1402.3614</a> <span> [<a href="https://arxiv.org/pdf/1402.3614">pdf</a>, <a href="https://arxiv.org/ps/1402.3614">ps</a>, <a href="https://arxiv.org/format/1402.3614">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/10.1088/0067-0049/214/2/27">10.1088/0067-0049/214/2/27 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Properties of 42 Solar-type Kepler Targets from the Asteroseismic Modeling Portal </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Metcalfe%2C+T+S">T. S. Metcalfe</a>, <a href="/search/?searchtype=author&query=Creevey%2C+O+L">O. L. Creevey</a>, <a href="/search/?searchtype=author&query=Dogan%2C+G">G. Dogan</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">S. Mathur</a>, <a href="/search/?searchtype=author&query=Xu%2C+H">H. Xu</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Karoff%2C+C">C. Karoff</a>, <a href="/search/?searchtype=author&query=Trampedach%2C+R">R. Trampedach</a>, <a href="/search/?searchtype=author&query=Benomar%2C+O">O. Benomar</a>, <a href="/search/?searchtype=author&query=Brown%2C+B+P">B. P. Brown</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Campante%2C+T+L">T. L. Campante</a>, <a href="/search/?searchtype=author&query=Celik%2C+Z">Z. Celik</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">M. S. Cunha</a>, <a href="/search/?searchtype=author&query=Davies%2C+G+R">G. R. Davies</a>, <a href="/search/?searchtype=author&query=Deheuvels%2C+S">S. Deheuvels</a>, <a href="/search/?searchtype=author&query=Derekas%2C+A">A. Derekas</a>, <a href="/search/?searchtype=author&query=Di+Mauro%2C+M+P">M. P. Di Mauro</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">R. A. Garcia</a>, <a href="/search/?searchtype=author&query=Guzik%2C+J+A">J. A. Guzik</a>, <a href="/search/?searchtype=author&query=Howe%2C+R">R. Howe</a>, <a href="/search/?searchtype=author&query=MacGregor%2C+K+B">K. B. MacGregor</a>, <a href="/search/?searchtype=author&query=Mazumdar%2C+A">A. Mazumdar</a> , et al. (17 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="1402.3614v3-abstract-short" style="display: inline;"> Recently the number of main-sequence and subgiant stars exhibiting solar-like oscillations that are resolved into individual mode frequencies has increased dramatically. While only a few such data sets were available for detailed modeling just a decade ago, the Kepler mission has produced suitable observations for hundreds of new targets. This rapid expansion in observational capacity has been acc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1402.3614v3-abstract-full').style.display = 'inline'; document.getElementById('1402.3614v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1402.3614v3-abstract-full" style="display: none;"> Recently the number of main-sequence and subgiant stars exhibiting solar-like oscillations that are resolved into individual mode frequencies has increased dramatically. While only a few such data sets were available for detailed modeling just a decade ago, the Kepler mission has produced suitable observations for hundreds of new targets. This rapid expansion in observational capacity has been accompanied by a shift in analysis and modeling strategies to yield uniform sets of derived stellar properties more quickly and easily. We use previously published asteroseismic and spectroscopic data sets to provide a uniform analysis of 42 solar-type Kepler targets from the Asteroseismic Modeling Portal (AMP). We find that fitting the individual frequencies typically doubles the precision of the asteroseismic radius, mass and age compared to grid-based modeling of the global oscillation properties, and improves the precision of the radius and mass by about a factor of three over empirical scaling relations. We demonstrate the utility of the derived properties with several applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1402.3614v3-abstract-full').style.display = 'none'; document.getElementById('1402.3614v3-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 September, 2014; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 February, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2014. </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">12 emulateapj pages, 9 figures, 1 online-only extended figure, 1 table, ApJS accepted (typo corrected in Eq.8)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astrophys.J.Supp.214:27,2014 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1309.0702">arXiv:1309.0702</a> <span> [<a href="https://arxiv.org/pdf/1309.0702">pdf</a>, <a href="https://arxiv.org/ps/1309.0702">ps</a>, <a href="https://arxiv.org/format/1309.0702">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"> Kepler White Paper: Asteroseismology of Solar-Like Oscillators in a 2-Wheel Mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J Chaplin</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Gilliland%2C+R+L">R. L. Gilliland</a>, <a href="/search/?searchtype=author&query=Kawaler%2C+S+D">S. D. Kawaler</a>, <a href="/search/?searchtype=author&query=Basu%2C+S">S. Basu</a>, <a href="/search/?searchtype=author&query=De+Ridder%2C+J">J. De Ridder</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">D. Huber</a>, <a href="/search/?searchtype=author&query=Arentoft%2C+T">T. Arentoft</a>, <a href="/search/?searchtype=author&query=Schou%2C+J">J. Schou</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">R. A. Garcia</a>, <a href="/search/?searchtype=author&query=Metcalfe%2C+T+S">T. S. Metcalfe</a>, <a href="/search/?searchtype=author&query=Brogaard%2C+K">K. Brogaard</a>, <a href="/search/?searchtype=author&query=Campante%2C+T+L">T. L. Campante</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y">Y. Elsworth</a>, <a href="/search/?searchtype=author&query=Miglio%2C+A">A. Miglio</a>, <a href="/search/?searchtype=author&query=Appourchaux%2C+T">T. Appourchaux</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Hekker%2C+S">S. Hekker</a>, <a href="/search/?searchtype=author&query=Houdek%2C+G">G. Houdek</a>, <a href="/search/?searchtype=author&query=Karoff%2C+C">C. Karoff</a>, <a href="/search/?searchtype=author&query=Molenda-Zakowicz%2C+J">J. Molenda-Zakowicz</a>, <a href="/search/?searchtype=author&query=Monteiro%2C+M+J+P+F+G">M. J. P. F. G. Monteiro</a>, <a href="/search/?searchtype=author&query=Aguirre%2C+V+S">V. Silva Aguirre</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">D. Stello</a> , et al. (31 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="1309.0702v1-abstract-short" style="display: inline;"> We comment on the potential for continuing asteroseismology of solar-type and red-giant stars in a 2-wheel Kepler Mission. Our main conclusion is that by targeting stars in the ecliptic it should be possible to perform high-quality asteroseismology, as long as favorable scenarios for 2-wheel pointing performance are met. Targeting the ecliptic would potentially facilitate unique science that was n… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1309.0702v1-abstract-full').style.display = 'inline'; document.getElementById('1309.0702v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1309.0702v1-abstract-full" style="display: none;"> We comment on the potential for continuing asteroseismology of solar-type and red-giant stars in a 2-wheel Kepler Mission. Our main conclusion is that by targeting stars in the ecliptic it should be possible to perform high-quality asteroseismology, as long as favorable scenarios for 2-wheel pointing performance are met. Targeting the ecliptic would potentially facilitate unique science that was not possible in the nominal Mission, notably from the study of clusters that are significantly brighter than those in the Kepler field. Our conclusions are based on predictions of 2-wheel observations made by a space photometry simulator, with information provided by the Kepler Project used as input to describe the degraded pointing scenarios. We find that elevated levels of frequency-dependent noise, consistent with the above scenarios, would have a significant negative impact on our ability to continue asteroseismic studies of solar-like oscillators in the Kepler field. However, the situation may be much more optimistic for observations in the ecliptic, provided that pointing resets of the spacecraft during regular desaturations of the two functioning reaction wheels are accurate at the < 1 arcsec level. This would make it possible to apply a post-hoc analysis that would recover most of the lost photometric precision. Without this post-hoc correction---and the accurate re-pointing it requires---the performance would probably be as poor as in the Kepler-field case. Critical to our conclusions for both fields is the assumed level of pointing noise (in the short-term jitter and the longer-term drift). We suggest that further tests will be needed to clarify our results once more detail and data on the expected pointing performance becomes available, and we offer our assistance in this work. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1309.0702v1-abstract-full').style.display = 'none'; document.getElementById('1309.0702v1-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 September, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2013. </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">NASA Kepler Mission White Paper; 10 pages, 2 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/1306.3306">arXiv:1306.3306</a> <span> [<a href="https://arxiv.org/pdf/1306.3306">pdf</a>, <a href="https://arxiv.org/ps/1306.3306">ps</a>, <a href="https://arxiv.org/format/1306.3306">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/stt964">10.1093/mnras/stt964 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Sounding stellar cycles with Kepler - II. Ground-based observations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Karoff%2C+C">C. Karoff</a>, <a href="/search/?searchtype=author&query=Metcalfe%2C+T+S">T. S. Metcalfe</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=Frandsen%2C+S">S. Frandsen</a>, <a href="/search/?searchtype=author&query=Grundahl%2C+F">F. Grundahl</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Nielsen%2C+M+B">M. B. Nielsen</a>, <a href="/search/?searchtype=author&query=Frimann%2C+S">S. Frimann</a>, <a href="/search/?searchtype=author&query=Thygesen%2C+A+O">A. O. Thygesen</a>, <a href="/search/?searchtype=author&query=Arentoft%2C+T">T. Arentoft</a>, <a href="/search/?searchtype=author&query=Amby%2C+T+M">T. M. Amby</a>, <a href="/search/?searchtype=author&query=Sousa%2C+S+G">S. G. Sousa</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</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="1306.3306v1-abstract-short" style="display: inline;"> We have monitored 20 Sun-like stars in the Kepler field-of-view for excess flux with the FIES spectrograph on the Nordic Optical Telescope since the launch of Kepler spacecraft in 2009. These 20 stars were selected based on their asteroseismic properties to sample the parameter space (effective temperature, surface gravity, activity level etc.) around the Sun. Though the ultimate goal is to improv… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.3306v1-abstract-full').style.display = 'inline'; document.getElementById('1306.3306v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1306.3306v1-abstract-full" style="display: none;"> We have monitored 20 Sun-like stars in the Kepler field-of-view for excess flux with the FIES spectrograph on the Nordic Optical Telescope since the launch of Kepler spacecraft in 2009. These 20 stars were selected based on their asteroseismic properties to sample the parameter space (effective temperature, surface gravity, activity level etc.) around the Sun. Though the ultimate goal is to improve stellar dynamo models, we focus the present paper on the combination of space-based and ground-based observations can be used to test the age-rotation-activity relations. In this paper we describe the considerations behind the selection of these 20 Sun-like stars and present an initial asteroseismic analysis, which includes stellar age estimates. We also describe the observations from the Nordic Optical Telescope and present mean values of measured excess fluxes. These measurements are combined with estimates of the rotation periods obtained from a simple analysis of the modulation in photometric observations from Kepler caused by starspots, and asteroseismic determinations of stellar ages, to test relations between between age, rotation and activity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.3306v1-abstract-full').style.display = 'none'; document.getElementById('1306.3306v1-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> 14 June, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2013. </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/1109.3460">arXiv:1109.3460</a> <span> [<a href="https://arxiv.org/pdf/1109.3460">pdf</a>, <a href="https://arxiv.org/ps/1109.3460">ps</a>, <a href="https://arxiv.org/format/1109.3460">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/10.1088/0004-637X/743/2/143">10.1088/0004-637X/743/2/143 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Testing Scaling Relations for Solar-Like Oscillations from the Main Sequence to Red Giants using Kepler Data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Huber%2C+D">D. Huber</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">D. Stello</a>, <a href="/search/?searchtype=author&query=Hekker%2C+S">S. Hekker</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">S. Mathur</a>, <a href="/search/?searchtype=author&query=Mosser%2C+B">B. Mosser</a>, <a href="/search/?searchtype=author&query=Verner%2C+G+A">G. A. Verner</a>, <a href="/search/?searchtype=author&query=Bonanno%2C+A">A. Bonanno</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Campante%2C+T+L">T. L. Campante</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y+P">Y. P. Elsworth</a>, <a href="/search/?searchtype=author&query=Hale%2C+S+J">S. J. Hale</a>, <a href="/search/?searchtype=author&query=Kallinger%2C+T">T. Kallinger</a>, <a href="/search/?searchtype=author&query=Aguirre%2C+V+S">V. Silva Aguirre</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=De+Ridder%2C+J">J. De Ridder</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">R. A. Garcia</a>, <a href="/search/?searchtype=author&query=Appourchaux%2C+T">T. Appourchaux</a>, <a href="/search/?searchtype=author&query=Frandsen%2C+S">S. Frandsen</a>, <a href="/search/?searchtype=author&query=Houdek%2C+G">G. Houdek</a>, <a href="/search/?searchtype=author&query=Molenda-Zakowicz%2C+J">J. Molenda-Zakowicz</a>, <a href="/search/?searchtype=author&query=Monteiro%2C+M+J+P+F+G">M. J. P. F. G. Monteiro</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Gilliland%2C+R+L">R. L. Gilliland</a>, <a href="/search/?searchtype=author&query=Kawaler%2C+S+D">S. D. Kawaler</a> , et al. (7 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="1109.3460v1-abstract-short" style="display: inline;"> We have analyzed solar-like oscillations in ~1700 stars observed by the Kepler Mission, spanning from the main-sequence to the red clump. Using evolutionary models, we test asteroseismic scaling relations for the frequency of maximum power (nu_max), the large frequency separation (Delta_nu) and oscillation amplitudes. We show that the difference of the Delta_nu-nu_max relation for unevolved and ev… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1109.3460v1-abstract-full').style.display = 'inline'; document.getElementById('1109.3460v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1109.3460v1-abstract-full" style="display: none;"> We have analyzed solar-like oscillations in ~1700 stars observed by the Kepler Mission, spanning from the main-sequence to the red clump. Using evolutionary models, we test asteroseismic scaling relations for the frequency of maximum power (nu_max), the large frequency separation (Delta_nu) and oscillation amplitudes. We show that the difference of the Delta_nu-nu_max relation for unevolved and evolved stars can be explained by different distributions in effective temperature and stellar mass, in agreement with what is expected from scaling relations. For oscillation amplitudes, we show that neither (L/M)^s scaling nor the revised scaling relation by Kjeldsen & Bedding (2011) are accurate for red-giant stars, and demonstrate that a revised scaling relation with a separate luminosity-mass dependence can be used to calculate amplitudes from the main-sequence to red-giants to a precision of ~25%. The residuals show an offset particularly for unevolved stars, suggesting that an additional physical dependency is necessary to fully reproduce the observed amplitudes. We investigate correlations between amplitudes and stellar activity, and find evidence that the effect of amplitude suppression is most pronounced for subgiant stars. Finally, we test the location of the cool edge of the instability strip in the Hertzsprung-Russell diagram using solar-like oscillations and find the detections in the hottest stars compatible with a domain of hybrid stochastically excited and opacity driven pulsation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1109.3460v1-abstract-full').style.display = 'none'; document.getElementById('1109.3460v1-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, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2011. </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">11 pages, 9 figures, 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/1107.5207">arXiv:1107.5207</a> <span> [<a href="https://arxiv.org/pdf/1107.5207">pdf</a>, <a href="https://arxiv.org/ps/1107.5207">ps</a>, <a href="https://arxiv.org/format/1107.5207">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/10.1088/0067-0049/197/1/6">10.1088/0067-0049/197/1/6 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Kepler Mission Stellar and Instrument Noise Properties </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Gilliland%2C+R+L">Ronald L. Gilliland</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Dunham%2C+E+W">Edward W. Dunham</a>, <a href="/search/?searchtype=author&query=Argabright%2C+V+S">Vic S. Argabright</a>, <a href="/search/?searchtype=author&query=Borucki%2C+W+J">William J. Borucki</a>, <a href="/search/?searchtype=author&query=Basri%2C+G">Gibor Basri</a>, <a href="/search/?searchtype=author&query=Bryson%2C+S+T">Stephen T. Bryson</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Caldwell%2C+D+A">Douglas A. Caldwell</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y+P">Yvonne P. Elsworth</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J+M">Jon M. Jenkins</a>, <a href="/search/?searchtype=author&query=Koch%2C+D+G">David G. Koch</a>, <a href="/search/?searchtype=author&query=Kolodziejczak%2C+J">Jeffrey Kolodziejczak</a>, <a href="/search/?searchtype=author&query=Miglio%2C+A">Andrea Miglio</a>, <a href="/search/?searchtype=author&query=van+Cleve%2C+J">Jeffrey van Cleve</a>, <a href="/search/?searchtype=author&query=Walkowicz%2C+L+M">Lucianne M. Walkowicz</a>, <a href="/search/?searchtype=author&query=Welsh%2C+W+F">William F. Welsh</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="1107.5207v1-abstract-short" style="display: inline;"> Kepler Mission results are rapidly contributing to fundamentally new discoveries in both the exoplanet and asteroseismology fields. The data returned from Kepler are unique in terms of the number of stars observed, precision of photometry for time series observations, and the temporal extent of high duty cycle observations. As the first mission to provide extensive time series measurements on thou… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1107.5207v1-abstract-full').style.display = 'inline'; document.getElementById('1107.5207v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1107.5207v1-abstract-full" style="display: none;"> Kepler Mission results are rapidly contributing to fundamentally new discoveries in both the exoplanet and asteroseismology fields. The data returned from Kepler are unique in terms of the number of stars observed, precision of photometry for time series observations, and the temporal extent of high duty cycle observations. As the first mission to provide extensive time series measurements on thousands of stars over months to years at a level hitherto possible only for the Sun, the results from Kepler will vastly increase our knowledge of stellar variability for quiet solar-type stars. Here we report on the stellar noise inferred on the timescale of a few hours of most interest for detection of exoplanets via transits. By design the data from moderately bright Kepler stars are expected to have roughly comparable levels of noise intrinsic to the stars and arising from a combination of fundamental limitations such as Poisson statistics and any instrument noise. The noise levels attained by Kepler on-orbit exceed by some 50% the target levels for solar-type, quiet stars. We provide a decomposition of observed noise for an ensemble of 12th magnitude stars arising from fundamental terms (Poisson and readout noise), added noise due to the instrument and that intrinsic to the stars. The largest factor in the modestly higher than anticipated noise follows from intrinsic stellar noise. We show that using stellar parameters from galactic stellar synthesis models, and projections to stellar rotation, activity and hence noise levels reproduces the primary intrinsic stellar noise features. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1107.5207v1-abstract-full').style.display = 'none'; document.getElementById('1107.5207v1-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 July, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2011. </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; 26 pages, 20 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/1103.5805">arXiv:1103.5805</a> <span> [<a href="https://arxiv.org/pdf/1103.5805">pdf</a>, <a href="https://arxiv.org/ps/1103.5805">ps</a>, <a href="https://arxiv.org/format/1103.5805">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/10.1038/nature09935">10.1038/nature09935 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Mosser%2C+B">Benoit Mosser</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">Daniel Huber</a>, <a href="/search/?searchtype=author&query=Montalban%2C+J">Josefina Montalban</a>, <a href="/search/?searchtype=author&query=Beck%2C+P">Paul Beck</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">Joergen Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y+P">Yvonne P. Elsworth</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">Rafael A. Garcia</a>, <a href="/search/?searchtype=author&query=Miglio%2C+A">Andrea Miglio</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">Dennis Stello</a>, <a href="/search/?searchtype=author&query=White%2C+T+R">Timothy R. White</a>, <a href="/search/?searchtype=author&query=De+Ridder%2C+J">Joris De Ridder</a>, <a href="/search/?searchtype=author&query=Hekker%2C+S">Saskia Hekker</a>, <a href="/search/?searchtype=author&query=Aerts%2C+C">Conny Aerts</a>, <a href="/search/?searchtype=author&query=Barban%2C+C">Caroline Barban</a>, <a href="/search/?searchtype=author&query=Belkacem%2C+K">Kevin Belkacem</a>, <a href="/search/?searchtype=author&query=Broomhall%2C+A">Anne-Marie Broomhall</a>, <a href="/search/?searchtype=author&query=Brown%2C+T+M">Timothy M. Brown</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Carrier%2C+F">Fabien Carrier</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">William J. Chaplin</a>, <a href="/search/?searchtype=author&query=Di+Mauro%2C+M+P">Maria Pia Di Mauro</a>, <a href="/search/?searchtype=author&query=Dupret%2C+M">Marc-Antoine Dupret</a>, <a href="/search/?searchtype=author&query=Frandsen%2C+S">Soeren Frandsen</a>, <a href="/search/?searchtype=author&query=Gilliland%2C+R+L">Ronald L. Gilliland</a> , et al. (9 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="1103.5805v1-abstract-short" style="display: inline;"> Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include uncertainties in the amount of mass lost at the surface before helium ignition and the amount of internal mixing… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1103.5805v1-abstract-full').style.display = 'inline'; document.getElementById('1103.5805v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1103.5805v1-abstract-full" style="display: none;"> Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include uncertainties in the amount of mass lost at the surface before helium ignition and the amount of internal mixing from rotation and other processes. Progress is hampered by our inability to distinguish between red giants burning helium in the core and those still only burning hydrogen in a shell. Asteroseismology offers a way forward, being a powerful tool for probing the internal structures of stars using their natural oscillation frequencies. Here we report observations of gravity-mode period spacings in red giants that permit a distinction between evolutionary stages to be made. We use high-precision photometry obtained with the Kepler spacecraft over more than a year to measure oscillations in several hundred red giants. We find many stars whose dipole modes show sequences with approximately regular period spacings. These stars fall into two clear groups, allowing us to distinguish unambiguously between hydrogen-shell-burning stars (period spacing mostly about 50 seconds) and those that are also burning helium (period spacing about 100 to 300 seconds). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1103.5805v1-abstract-full').style.display = 'none'; document.getElementById('1103.5805v1-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 March, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2011. </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">to appear as a Letter to Nature</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1010.4566">arXiv:1010.4566</a> <span> [<a href="https://arxiv.org/pdf/1010.4566">pdf</a>, <a href="https://arxiv.org/ps/1010.4566">ps</a>, <a href="https://arxiv.org/format/1010.4566">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/10.1088/0004-637X/723/2/1607">10.1088/0004-637X/723/2/1607 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Asteroseismology of red giants from the first four months of Kepler data: Global oscillation parameters for 800 stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Huber%2C+D">D. Huber</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">D. Stello</a>, <a href="/search/?searchtype=author&query=Mosser%2C+B">B. Mosser</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">S. Mathur</a>, <a href="/search/?searchtype=author&query=Kallinger%2C+T">T. Kallinger</a>, <a href="/search/?searchtype=author&query=Hekker%2C+S">S. Hekker</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y+P">Y. P. Elsworth</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=De+Ridder%2C+J">J. De Ridder</a>, <a href="/search/?searchtype=author&query=Gilliland%2C+R+L">R. L. Gilliland</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">R. A. Garcia</a>, <a href="/search/?searchtype=author&query=Hale%2C+S+J">S. J. Hale</a>, <a href="/search/?searchtype=author&query=Preston%2C+H+L">H. L. Preston</a>, <a href="/search/?searchtype=author&query=White%2C+T+R">T. R. White</a>, <a href="/search/?searchtype=author&query=Borucki%2C+W+J">W. J. Borucki</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Clarke%2C+B+D">B. D. Clarke</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J+M">J. M. Jenkins</a>, <a href="/search/?searchtype=author&query=Koch%2C+D">D. Koch</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="1010.4566v1-abstract-short" style="display: inline;"> We have studied solar-like oscillations in ~800 red-giant stars using Kepler long-cadence photometry. The sample includes stars ranging in evolution from the lower part of the red-giant branch to the Helium main sequence. We investigate the relation between the large frequency separation (Delta nu) and the frequency of maximum power (nu_max) and show that it is different for red giants than for ma… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1010.4566v1-abstract-full').style.display = 'inline'; document.getElementById('1010.4566v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1010.4566v1-abstract-full" style="display: none;"> We have studied solar-like oscillations in ~800 red-giant stars using Kepler long-cadence photometry. The sample includes stars ranging in evolution from the lower part of the red-giant branch to the Helium main sequence. We investigate the relation between the large frequency separation (Delta nu) and the frequency of maximum power (nu_max) and show that it is different for red giants than for main-sequence stars, which is consistent with evolutionary models and scaling relations. The distributions of nu_max and Delta nu are in qualitative agreement with a simple stellar population model of the Kepler field, including the first evidence for a secondary clump population characterized by M ~> 2 M_sun and nu_max ~ 40-110 muHz. We measured the small frequency separations delta nu_02 and delta nu_01 in over 400 stars and delta nu_03 in over 40. We present C-D diagrams for l=1, 2 and 3 and show that the frequency separation ratios delta nu_02/Delta nu and delta nu_01/Delta nu have opposite trends as a function of Delta nu. The data show a narrowing of the l=1 ridge towards lower nu_max, in agreement with models predicting more efficient mode trapping in stars with higher luminosity. We investigate the offset epsilon in the asymptotic relation and find a clear correlation with Delta nu, demonstrating that it is related to fundamental stellar parameters. Finally, we present the first amplitude-nu_max relation for Kepler red giants. We observe a lack of low-amplitude stars for nu_max ~> 110 muHz and find that, for a given nu_max between 40-110 muHz, stars with lower Delta nu (and consequently higher mass) tend to show lower amplitudes than stars with higher Delta nu. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1010.4566v1-abstract-full').style.display = 'none'; document.getElementById('1010.4566v1-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, 2010; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2010. </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">12 pages, 12 figures, 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/1008.2959">arXiv:1008.2959</a> <span> [<a href="https://arxiv.org/pdf/1008.2959">pdf</a>, <a href="https://arxiv.org/ps/1008.2959">ps</a>, <a href="https://arxiv.org/format/1008.2959">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/10.1051/0004-6361/201015185">10.1051/0004-6361/201015185 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Solar-like oscillations in red giants observed with Kepler: comparison of global oscillation parameters from different methods </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Hekker%2C+S">S. Hekker</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y">Y. Elsworth</a>, <a href="/search/?searchtype=author&query=De+Ridder%2C+J">J. De Ridder</a>, <a href="/search/?searchtype=author&query=Mosser%2C+B">B. Mosser</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">R. A. Garcia</a>, <a href="/search/?searchtype=author&query=Kallinger%2C+T">T. Kallinger</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">S. Mathur</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">D. Huber</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Preston%2C+H+L">H. L. Preston</a>, <a href="/search/?searchtype=author&query=Hale%2C+S+J">S. J. Hale</a>, <a href="/search/?searchtype=author&query=Ballot%2C+J">J. Ballot</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=Regulo%2C+C">C. Regulo</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">D. Stello</a>, <a href="/search/?searchtype=author&query=Borucki%2C+W+J">W. J. Borucki</a>, <a href="/search/?searchtype=author&query=Koch%2C+D+G">D. G. Koch</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J">J. Jenkins</a>, <a href="/search/?searchtype=author&query=Allen%2C+C">C. Allen</a>, <a href="/search/?searchtype=author&query=Gilliland%2C+R+L">R. L. Gilliland</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</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="1008.2959v1-abstract-short" style="display: inline;"> The large number of stars for which uninterrupted high-precision photometric timeseries data are being collected with \textit{Kepler} and CoRoT initiated the development of automated methods to analyse the stochastically excited oscillations in main-sequence, subgiant and red-giant stars. Aims: We investigate the differences in results for global oscillation parameters of G and K red-giant stars d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1008.2959v1-abstract-full').style.display = 'inline'; document.getElementById('1008.2959v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1008.2959v1-abstract-full" style="display: none;"> The large number of stars for which uninterrupted high-precision photometric timeseries data are being collected with \textit{Kepler} and CoRoT initiated the development of automated methods to analyse the stochastically excited oscillations in main-sequence, subgiant and red-giant stars. Aims: We investigate the differences in results for global oscillation parameters of G and K red-giant stars due to different methods and definitions. We also investigate uncertainties originating from the stochastic nature of the oscillations. Methods: For this investigation we use Kepler data obtained during the first four months of operation. These data have been analysed by different groups using already published methods and the results are compared. We also performed simulations to investigate the uncertainty on the resulting parameters due to different realizations of the stochastic signal. Results: We obtain results for the frequency of maximum oscillation power (nu_max) and the mean large separation (<delta nu>) from different methods for over one thousand red-giant stars. The results for these parameters agree within a few percent and seem therefore robust to the different analysis methods and definitions used here. The uncertainties for nu_max and <delta nu> due to differences in realization noise are not negligible and should be taken into account when using these results for stellar modelling. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1008.2959v1-abstract-full').style.display = 'none'; document.getElementById('1008.2959v1-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 August, 2010; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2010. </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">11 pages, 9 Figures and 7 tables, accepted for publication in Astronomy and 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/1001.0506">arXiv:1001.0506</a> <span> [<a href="https://arxiv.org/pdf/1001.0506">pdf</a>, <a href="https://arxiv.org/ps/1001.0506">ps</a>, <a href="https://arxiv.org/format/1001.0506">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/10.1088/2041-8205/713/2/L169">10.1088/2041-8205/713/2/L169 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The asteroseismic potential of Kepler: first results for solar-type stars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=Appourchaux%2C+T">T. Appourchaux</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y">Y. Elsworth</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">R. A. Garcia</a>, <a href="/search/?searchtype=author&query=Houdek%2C+G">G. Houdek</a>, <a href="/search/?searchtype=author&query=Karoff%2C+C">C. Karoff</a>, <a href="/search/?searchtype=author&query=Metcalfe%2C+T+S">T. S. Metcalfe</a>, <a href="/search/?searchtype=author&query=Molenda-Zakowicz%2C+J">J. Molenda-Zakowicz</a>, <a href="/search/?searchtype=author&query=Monteiro%2C+M+J+P+F+G">M. J. P. F. G. Monteiro</a>, <a href="/search/?searchtype=author&query=Thompson%2C+M+J">M. J. Thompson</a>, <a href="/search/?searchtype=author&query=Brown%2C+T+M">T. M. Brown</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Gilliland%2C+R+L">R. L. Gilliland</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a>, <a href="/search/?searchtype=author&query=Borucki%2C+W+J">W. J. Borucki</a>, <a href="/search/?searchtype=author&query=Koch%2C+D">D. Koch</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J+M">J. M. Jenkins</a>, <a href="/search/?searchtype=author&query=Ballot%2C+J">J. Ballot</a>, <a href="/search/?searchtype=author&query=Basu%2C+S">S. Basu</a>, <a href="/search/?searchtype=author&query=Bazot%2C+M">M. Bazot</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Benomar%2C+O">O. Benomar</a>, <a href="/search/?searchtype=author&query=Bonanno%2C+A">A. Bonanno</a>, <a href="/search/?searchtype=author&query=Brandao%2C+I+M">I. M. Brandao</a>, <a href="/search/?searchtype=author&query=Bruntt%2C+H">H. Bruntt</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="1001.0506v2-abstract-short" style="display: inline;"> We present preliminary asteroseismic results from Kepler on three G-type stars. The observations, made at one-minute cadence during the first 33.5d of science operations, reveal high signal-to-noise solar-like oscillation spectra in all three stars: About 20 modes of oscillation may be clearly distinguished in each star. We discuss the appearance of the oscillation spectra, use the frequencies a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1001.0506v2-abstract-full').style.display = 'inline'; document.getElementById('1001.0506v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1001.0506v2-abstract-full" style="display: none;"> We present preliminary asteroseismic results from Kepler on three G-type stars. The observations, made at one-minute cadence during the first 33.5d of science operations, reveal high signal-to-noise solar-like oscillation spectra in all three stars: About 20 modes of oscillation may be clearly distinguished in each star. We discuss the appearance of the oscillation spectra, use the frequencies and frequency separations to provide first results on the radii, masses and ages of the stars, and comment in the light of these results on prospects for inference on other solar-type stars that Kepler will observe. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1001.0506v2-abstract-full').style.display = 'none'; document.getElementById('1001.0506v2-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 January, 2010; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 January, 2010; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2010. </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, 3 figures, 1 table; now accepted for publication in 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/1001.0229">arXiv:1001.0229</a> <span> [<a href="https://arxiv.org/pdf/1001.0229">pdf</a>, <a href="https://arxiv.org/ps/1001.0229">ps</a>, <a href="https://arxiv.org/format/1001.0229">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/10.1088/2041-8205/713/2/L176">10.1088/2041-8205/713/2/L176 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Solar-like oscillations in low-luminosity red giants: first results from Kepler </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Huber%2C+D">D. Huber</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">D. Stello</a>, <a href="/search/?searchtype=author&query=Elsworth%2C+Y+P">Y. P. Elsworth</a>, <a href="/search/?searchtype=author&query=Hekker%2C+S">S. Hekker</a>, <a href="/search/?searchtype=author&query=Kallinger%2C+T">T. Kallinger</a>, <a href="/search/?searchtype=author&query=Mathur%2C+S">S. Mathur</a>, <a href="/search/?searchtype=author&query=Mosser%2C+B">B. Mosser</a>, <a href="/search/?searchtype=author&query=Preston%2C+H+L">H. L. Preston</a>, <a href="/search/?searchtype=author&query=Ballot%2C+J">J. Ballot</a>, <a href="/search/?searchtype=author&query=Barban%2C+C">C. Barban</a>, <a href="/search/?searchtype=author&query=Broomhall%2C+A+M">A. M. Broomhall</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Chaplin%2C+W+J">W. J. Chaplin</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+A">R. A. Garcia</a>, <a href="/search/?searchtype=author&query=Gruberbauer%2C+M">M. Gruberbauer</a>, <a href="/search/?searchtype=author&query=Hale%2C+S+J">S. J. Hale</a>, <a href="/search/?searchtype=author&query=De+Ridder%2C+J">J. De Ridder</a>, <a href="/search/?searchtype=author&query=Frandsen%2C+S">S. Frandsen</a>, <a href="/search/?searchtype=author&query=Borucki%2C+W+J">W. J. Borucki</a>, <a href="/search/?searchtype=author&query=Brown%2C+T">T. Brown</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Gilliland%2C+R+L">R. L. Gilliland</a>, <a href="/search/?searchtype=author&query=Jenkins%2C+J+M">J. M. Jenkins</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a> , et al. (25 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="1001.0229v2-abstract-short" style="display: inline;"> We have measured solar-like oscillations in red giants using time-series photometry from the first 34 days of science operations of the Kepler Mission. The light curves, obtained with 30-minute sampling, reveal clear oscillations in a large sample of G and K giants, extending in luminosity from the red clump down to the bottom of the giant branch. We confirm a strong correlation between the larg… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1001.0229v2-abstract-full').style.display = 'inline'; document.getElementById('1001.0229v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1001.0229v2-abstract-full" style="display: none;"> We have measured solar-like oscillations in red giants using time-series photometry from the first 34 days of science operations of the Kepler Mission. The light curves, obtained with 30-minute sampling, reveal clear oscillations in a large sample of G and K giants, extending in luminosity from the red clump down to the bottom of the giant branch. We confirm a strong correlation between the large separation of the oscillations (Delta nu) and the frequency of maximum power (nu_max). We focus on a sample of 50 low-luminosity stars (nu_max > 100 muHz, L <~ 30 L_sun) having high signal-to-noise ratios and showing the unambiguous signature of solar-like oscillations. These are H-shell-burning stars, whose oscillations should be valuable for testing models of stellar evolution and for constraining the star-formation rate in the local disk. We use a new technique to compare stars on a single echelle diagram by scaling their frequencies and find well-defined ridges corresponding to radial and non-radial oscillations, including clear evidence for modes with angular degree l=3. Measuring the small separation between l=0 and l=2 allows us to plot the so-called C-D diagram of delta nu_02 versus Delta nu. The small separation delta nu_01 of l=1 from the midpoint of adjacent l=0 modes is negative, contrary to the Sun and solar-type stars. The ridge for l=1 is notably broadened, which we attribute to mixed modes, confirming theoretical predictions for low-luminosity giants. Overall, the results demonstrate the tremendous potential of Kepler data for asteroseismology of red giants. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1001.0229v2-abstract-full').style.display = 'none'; document.getElementById('1001.0229v2-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 January, 2010; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 January, 2010; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2010. </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 Letters, to appear in special Kepler issue. Updated references</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0903.3967">arXiv:0903.3967</a> <span> [<a href="https://arxiv.org/pdf/0903.3967">pdf</a>, <a href="https://arxiv.org/ps/0903.3967">ps</a>, <a href="https://arxiv.org/format/0903.3967">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/10.1111/j.1365-2966.2009.14804.x">10.1111/j.1365-2966.2009.14804.x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Asteroseismic analysis of the roAp star alpha Circini: 84 days of high-precision photometry from the WIRE satellite </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bruntt%2C+H">H. Bruntt</a>, <a href="/search/?searchtype=author&query=Kurtz%2C+D+W">D. W. Kurtz</a>, <a href="/search/?searchtype=author&query=Cunha%2C+M+S">M. S. Cunha</a>, <a href="/search/?searchtype=author&query=Brandao%2C+I+M">I. M. Brandao</a>, <a href="/search/?searchtype=author&query=Handler%2C+G">G. Handler</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Medupe%2C+T">T. Medupe</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Mashigo%2C+D">D. Mashigo</a>, <a href="/search/?searchtype=author&query=Zhang%2C+I">I. Zhang</a>, <a href="/search/?searchtype=author&query=van+Wyk%2C+F">F. van Wyk</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="0903.3967v1-abstract-short" style="display: inline;"> We present a detailed study of the pulsation of alpha Circini, the brightest of the rapidly oscillating Ap stars. We have obtained 84 days of high-precision photometry from four runs with the star tracker on the WIRE satellite. Simultaneously, we collected ground-based Johnson B observations on 16 nights at the South African Astronomical Observatory. In addition to the dominant oscillation mode… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0903.3967v1-abstract-full').style.display = 'inline'; document.getElementById('0903.3967v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0903.3967v1-abstract-full" style="display: none;"> We present a detailed study of the pulsation of alpha Circini, the brightest of the rapidly oscillating Ap stars. We have obtained 84 days of high-precision photometry from four runs with the star tracker on the WIRE satellite. Simultaneously, we collected ground-based Johnson B observations on 16 nights at the South African Astronomical Observatory. In addition to the dominant oscillation mode at 2442 microHz, we detect two new modes that lie symmetrically around the principal mode to form a triplet. The average separation between these modes is 30.173+-0.004 microHz and they are nearly equidistant with the separations differing by only 3.9 nHz. We compare the observed frequencies with theoretical pulsation models based on constraints from the recently determined interferometric radius and effective temperature, and the recently updated Hipparcos parallax. We show that the theoretical large separations for models of alpha Cir with global parameters within the 1-sigma observational uncertainties vary between 59 and 65 microHz. This is consistent with the large separation being twice the observed value, indicating that the three main modes are of alternating even and odd degrees. The frequency differences in the triplet are significantly smaller than those predicted from our models, for all possible combinations of mode degrees, and may indicate that the effects of magnetic perturbations need to be taken into account. The WIRE light curves are modulated by a double wave with a period of 4.479 days, and a peak-to-peak amplitude of 4 mmag. This variation is due to the rotation of the star and is a new discovery, made possible by the high precision of the WIRE photometry. The rotational modulation confirms an earlier indirect determination of the rotation period. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0903.3967v1-abstract-full').style.display = 'none'; document.getElementById('0903.3967v1-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 March, 2009; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2009. </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 MNRAS. The resolution of Figs. 1 and 5 has been degraded. Abstract abridged. 14 pages, 10 Figs</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0804.3593">arXiv:0804.3593</a> <span> [<a href="https://arxiv.org/pdf/0804.3593">pdf</a>, <a href="https://arxiv.org/ps/0804.3593">ps</a>, <a href="https://arxiv.org/format/0804.3593">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1086/589565">10.1086/589565 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Polaris the Cepheid returns: 4.5 years of monitoring from ground and space </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bruntt%2C+H">H. Bruntt</a>, <a href="/search/?searchtype=author&query=Evans%2C+N+R">N. R. Evans</a>, <a href="/search/?searchtype=author&query=Stello%2C+D">D. Stello</a>, <a href="/search/?searchtype=author&query=Penny%2C+A+J">A. J. Penny</a>, <a href="/search/?searchtype=author&query=Eaton%2C+J+A">J. A. Eaton</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Sasselov%2C+D+D">D. D. Sasselov</a>, <a href="/search/?searchtype=author&query=Preston%2C+H+L">H. L. Preston</a>, <a href="/search/?searchtype=author&query=Miller-Ricci%2C+E">E. Miller-Ricci</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="0804.3593v1-abstract-short" style="display: inline;"> We present the analysis of 4.5 years of nearly continuous observations of the classical Cepheid Polaris, which comprise the most precise data available for this star. We have made spectroscopic measurements from ground and photometric measurements from the WIRE star tracker and the SMEI instrument on the Coriolis satellite. Measurements of the amplitude of the dominant oscillation (P = 4 days),… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0804.3593v1-abstract-full').style.display = 'inline'; document.getElementById('0804.3593v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0804.3593v1-abstract-full" style="display: none;"> We present the analysis of 4.5 years of nearly continuous observations of the classical Cepheid Polaris, which comprise the most precise data available for this star. We have made spectroscopic measurements from ground and photometric measurements from the WIRE star tracker and the SMEI instrument on the Coriolis satellite. Measurements of the amplitude of the dominant oscillation (P = 4 days), that go back more than a century, show a decrease from 120 mmag to 30 mmag (V magnitude) around the turn of the millennium. It has been speculated that the reason for the decrease in amplitude is the evolution of Polaris towards the edge of the instability strip. However, our new data reveal an increase in the amplitude by about 30% from 2003-2006. It now appears that the amplitude change is cyclic rather than monotonic, and most likely the result of a pulsation phenomenon. In addition, previous radial velocity campaigns have claimed the detection of long-period variation in Polaris (P > 40 days). Our radial velocity data are more precise than previous datasets, and we find no evidence for additional variation for periods in the range 3-50 days with an upper limit of 100 m/s. However, in the WIRE data we find evidence of variation on time-scales of 2-6 days, which we interpret as being due to granulation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0804.3593v1-abstract-full').style.display = 'none'; document.getElementById('0804.3593v1-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 April, 2008; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2008. </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. 8 pages. Quality of figures 1+3+7 degraded</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0703634">arXiv:astro-ph/0703634</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0703634">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0703634">ps</a>, <a href="https://arxiv.org/format/astro-ph/0703634">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1051/0004-6361:20077184">10.1051/0004-6361:20077184 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Eclipsing binaries observed with the WIRE satellite. II. beta Aurigae and non-linear limb darkening in light curves </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Southworth%2C+J">John Southworth</a>, <a href="/search/?searchtype=author&query=Bruntt%2C+H">Hans Bruntt</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</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="astro-ph/0703634v1-abstract-short" style="display: inline;"> We present the most precise light curve ever obtained of a detached eclipsing binary star and use it investigate the inclusion of non-linear limb darkening laws in eclipsing binary light curve models. This light curve, of the bright system beta Aurigae, was obtained using the star tracker aboard the WIRE satellite and contains 30000 datapoints with a scatter of 0.3 mmag. We analyse it using a ve… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0703634v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0703634v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0703634v1-abstract-full" style="display: none;"> We present the most precise light curve ever obtained of a detached eclipsing binary star and use it investigate the inclusion of non-linear limb darkening laws in eclipsing binary light curve models. This light curve, of the bright system beta Aurigae, was obtained using the star tracker aboard the WIRE satellite and contains 30000 datapoints with a scatter of 0.3 mmag. We analyse it using a version of the EBOP code modified to include non-linear limb darkening and to directly incorporate observed times of minimum light and spectroscopic light ratios into the solution as individual observations. We also analyse the dataset with the WD code to ensure that the two models give consistent results. EBOP provides an excellent fit to the WIRE data. Whilst the fractional radii are only defined to a precision of 5%, including an accurate published spectroscopic light ratio improves this dramatically to 0.5%. Using non-linear limb darkening improves the quality of the fit significantly and causes the measured radii to increase by 0.4%. It is possible to derive all of the limb darkening coefficients from the light curve, although they are strongly correlated with each other, and they agree with theoretical predictions. The radii and masses of the components of beta Aur are R_A = 2.762 +/- 0.017 Rsun, R_B = 2.568 +/- 0.017 Rsun, M_A = 2.376 +/- 0.027 Msun and M_B = 2.291 +/- 0.027 Msun. Theoretical stellar models can match these parameters for a solar metal abundance and an age of 450-500 Myr. The Hipparcos trigonometric parallax and an interferometrically-derived orbital parallax give distances to beta Aur which are in excellent agreement with each other and with distances derived using surface brightness relations and several sets of empirical and theoretical bolometric corrections (abridged). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0703634v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0703634v1-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 March, 2007; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2007. </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, 3 figures, accepted by A&A. The (marvellous) WIRE light curve is available from CDS. The analysis code and WIRE light curve are available from http://www.astro.keele.ac.uk/~jkt</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astron.Astrophys.467:1215-1226,2007 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0610539">arXiv:astro-ph/0610539</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0610539">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0610539">ps</a>, <a href="https://arxiv.org/format/astro-ph/0610539">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1051/0004-6361:20065766">10.1051/0004-6361:20065766 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Asteroseismology with the WIRE satellite. I. Combining Ground- and Space-based Photometry of the Delta Scuti Star Epsilon Cephei </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bruntt%2C+H">H. Bruntt</a>, <a href="/search/?searchtype=author&query=Suarez%2C+J+C">J. C. Suarez</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Moya%2C+A">A. Moya</a>, <a href="/search/?searchtype=author&query=Amado%2C+P+J">P. J. Amado</a>, <a href="/search/?searchtype=author&query=Martin-Ruiz%2C+S">S. Martin-Ruiz</a>, <a href="/search/?searchtype=author&query=Garrido%2C+R">R. Garrido</a>, <a href="/search/?searchtype=author&query=de+Coca%2C+P+L">P. Lopez de Coca</a>, <a href="/search/?searchtype=author&query=Rolland%2C+A">A. Rolland</a>, <a href="/search/?searchtype=author&query=Costa%2C+V">V. Costa</a>, <a href="/search/?searchtype=author&query=Olivares%2C+I">I. Olivares</a>, <a href="/search/?searchtype=author&query=Garcia-Pelayo%2C+J+M">J. M. Garcia-Pelayo</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="astro-ph/0610539v1-abstract-short" style="display: inline;"> We have analysed ground-based multi-colour Stromgren photometry and single-filter photometry from the star tracker on the WIRE satellite of the delta scuti star Epsilon Cephei. The ground-based data set consists of 16 nights of data collected over 164 days, while the satellite data are nearly continuous coverage of the star during 14 days. The spectral window and noise level of the satellite dat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0610539v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0610539v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0610539v1-abstract-full" style="display: none;"> We have analysed ground-based multi-colour Stromgren photometry and single-filter photometry from the star tracker on the WIRE satellite of the delta scuti star Epsilon Cephei. The ground-based data set consists of 16 nights of data collected over 164 days, while the satellite data are nearly continuous coverage of the star during 14 days. The spectral window and noise level of the satellite data are superior to the ground-based data and this data set is used to locate the frequencies. However, we can use the ground-based data to improve the accuracy of the frequencies due to the much longer time baseline. We detect 26 oscillation frequencies in the WIRE data set, but only some of these can be seen clearly in the ground-based data. We have used the multi-colour ground-based photometry to determine amplitude and phase differences in the Stromgren b-y colour and the y filter in an attempt to identify the radial degree of the oscillation frequencies. We conclude that the accuracies of the amplitudes and phases are not sufficient to constrain theoretical models of Epsilon Cephei. We find no evidence for rotational splitting or the large separation among the frequencies detected in the WIRE data set. To be able to identify oscillation frequencies in delta scuti stars with the method we have applied, it is crucial to obtain more complete coverage from multi-site campaigns with a long time baseline and in multiple filters. This is important when planning photometric and spectroscopic ground-based support for future satellite missions like COROT and KEPLER. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0610539v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0610539v1-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 October, 2006; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2006. </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">13 pages, 12 figures, 4 tables. Fig. 4 reduced in quality. Accepted by 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/astro-ph/0606690">arXiv:astro-ph/0606690</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0606690">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0606690">ps</a>, <a href="https://arxiv.org/format/astro-ph/0606690">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1086/507404">10.1086/507404 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> X-ray Spectroscopy of the Contact Binary VW Cephei </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Huenemoerder%2C+D+P">David P. Huenemoerder</a>, <a href="/search/?searchtype=author&query=Testa%2C+P">Paola Testa</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</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="astro-ph/0606690v1-abstract-short" style="display: inline;"> Short-period binaries represent extreme cases in the generation of stellar coronae via a rotational dynamo. Such stars are important for probing the origin and nature of coronae in the regimes of rapid rotation and activity saturation. VW Cep (P=0.28 d) is a relatively bright, partially eclipsing, and very active object. Light curves made from Chandra/HETGS data show flaring and rotational modul… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0606690v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0606690v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0606690v1-abstract-full" style="display: none;"> Short-period binaries represent extreme cases in the generation of stellar coronae via a rotational dynamo. Such stars are important for probing the origin and nature of coronae in the regimes of rapid rotation and activity saturation. VW Cep (P=0.28 d) is a relatively bright, partially eclipsing, and very active object. Light curves made from Chandra/HETGS data show flaring and rotational modulation, but no eclipses. Velocity modulation of emission lines indicates that one component dominates the X-ray emission. The emission measure is highly structured, having three peaks. Helium-like triplet lines give electron densities of about 3.0E+10 - 18.0E+10 /cm^3. We conclude that the corona is predominantly on the polar regions of the primary star and compact. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0606690v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0606690v1-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, 2006; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2006. </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 Astropysical Journal, 23 June 2006; 22 pages, 15 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astrophys.J.650:1119-1132,2006 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0606551">arXiv:astro-ph/0606551</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0606551">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0606551">ps</a>, <a href="https://arxiv.org/format/astro-ph/0606551">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1051/0004-6361:20065628">10.1051/0004-6361:20065628 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Eclipsing binaries observed with the WIRE satellite I. Discovery and photometric analysis of the new bright A0IV eclipsing binary Psi Centauri </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bruntt%2C+H">H. Bruntt</a>, <a href="/search/?searchtype=author&query=Southworth%2C+J">J. Southworth</a>, <a href="/search/?searchtype=author&query=Torres%2C+G">G. Torres</a>, <a href="/search/?searchtype=author&query=Penny%2C+A+J">A. J. Penny</a>, <a href="/search/?searchtype=author&query=Clausen%2C+J+V">J. V. Clausen</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</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="astro-ph/0606551v1-abstract-short" style="display: inline;"> Determinations of stellar mass and radius with realistic uncertainties at the level of 1% provide important constraints on models of stellar structure and evolution. We present a high-precision light curve of the A0IV star Psi Centauri, from the star tracker on board the WIRE satellite and the Solar Mass Ejection Imager camera on the Coriolis spacecraft. The data show that Psi Cen is an eccentri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0606551v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0606551v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0606551v1-abstract-full" style="display: none;"> Determinations of stellar mass and radius with realistic uncertainties at the level of 1% provide important constraints on models of stellar structure and evolution. We present a high-precision light curve of the A0IV star Psi Centauri, from the star tracker on board the WIRE satellite and the Solar Mass Ejection Imager camera on the Coriolis spacecraft. The data show that Psi Cen is an eccentric eclipsing binary system with a relatively long orbital period. The WIRE light curve extends over 28.7 nights and contains 41334 observations with 2 mmag point-to-point scatter. The eclipse depths are 0.28 and 0.16 mag, and show that the two eclipsing components of Psi Cen have very different radii. As a consequence, the secondary eclipse is total. We find the eccentricity to be e=0.55 with an orbital period of 38.8 days from combining the WIRE light curve with data taken over two years from the Solar Mass Ejection Imager camera. We have fitted the light curve with EBOP and have assessed the uncertainties of the resulting parameters using Monte Carlo simulations. The fractional radii of the stars and the inclination of the orbit have random errors of only 0.1% and 0.01 degrees, respectively, but the systematic uncertainty in these quantities may be somewhat larger. We have used photometric calibrations to estimate the effective temperatures of the components of Psi Cen to be 10450+-300 and 8800+-300 K, indicating masses of about 3.1 and 2.0 Msun. There is evidence in the WIRE light curve for g-mode pulsations in the primary star. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0606551v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0606551v1-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 June, 2006; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2006. </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">9 pages, 4 figures, accepted for publication in A&A. Photometric data will be made available at the CDS once the final version appears. The resolution in Fig. 1 has been reduced</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0509444">arXiv:astro-ph/0509444</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0509444">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0509444">ps</a>, <a href="https://arxiv.org/format/astro-ph/0509444">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> </div> </div> <p class="title is-5 mathjax"> High-precision photometry with the WIRE satellite </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bruntt%2C+H">H. Bruntt</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</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="astro-ph/0509444v1-abstract-short" style="display: inline;"> Around 200 bright stars (V < 6) have been monitored with the two-inch star tracker on the WIRE satellite since observations started in 1999. Here we present new results for the solar-like star Procyon A, the two Delta Scuti stars Altair and Epsilon Cephei, and the triple system Lambda Scorpii which consist of two B-type stars -- one of which we find to be an eclipsing binary. </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0509444v1-abstract-full" style="display: none;"> Around 200 bright stars (V < 6) have been monitored with the two-inch star tracker on the WIRE satellite since observations started in 1999. Here we present new results for the solar-like star Procyon A, the two Delta Scuti stars Altair and Epsilon Cephei, and the triple system Lambda Scorpii which consist of two B-type stars -- one of which we find to be an eclipsing binary. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0509444v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0509444v1-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, 2005; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2005. </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, conference proceedings, Workshop on Stellar Pulsation and Evolution, Rome, June 2005</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Mem.Soc.Ast.It.77:278-281,2006 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0504469">arXiv:astro-ph/0504469</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0504469">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0504469">ps</a>, <a href="https://arxiv.org/format/astro-ph/0504469">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1086/462401">10.1086/462401 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Evidence for Granulation and Oscillations in Procyon from Photometry with the WIRE satellite </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bruntt%2C+H">H. Bruntt</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</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="astro-ph/0504469v2-abstract-short" style="display: inline;"> We report evidence for the granulation signal in the star Procyon A, based on two photometric time series from the star tracker on the WIRE satellite. The power spectra show evidence of excess power around 1 milliHz, consistent with the detection of p-modes reported from radial velocity measurements. We see a significant increase in the noise level below 3 milliHz, which we interpret as the gran… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0504469v2-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0504469v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0504469v2-abstract-full" style="display: none;"> We report evidence for the granulation signal in the star Procyon A, based on two photometric time series from the star tracker on the WIRE satellite. The power spectra show evidence of excess power around 1 milliHz, consistent with the detection of p-modes reported from radial velocity measurements. We see a significant increase in the noise level below 3 milliHz, which we interpret as the granulation signal. We have made a large set of numerical simulations to constrain the amplitude and timescale of the granulation signal and the amplitude of the oscillations. We find that the timescale for granulation is T(gran) = 750(200) s, the granulation amplitude is 1.8(0.3) times solar, and the amplitude of the p-modes is 8(3) ppm. We found the distribution of peak heights in the observed power spectra to be consistent with that expected from p-mode oscillations. However, the quality of the data is not sufficient to measure the large separation or detect a comb-like structure, as seen in the p-modes of the Sun. Comparison with the recent negative result from the MOST satellite reveal that the MOST data must have an additional noise source that prevented the detection of oscillations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0504469v2-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0504469v2-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 April, 2005; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 April, 2005; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2005. </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, 12 figures, submitted to ApJ; v2 revisions: one reference corrected and a comment in Figure 7 corrected</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astrophys.J. 633 (2005) 440-446 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0501662">arXiv:astro-ph/0501662</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0501662">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0501662">ps</a>, <a href="https://arxiv.org/format/astro-ph/0501662">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1051/0004-6361:200500019">10.1051/0004-6361:200500019 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The non-detection of oscillations in Procyon by MOST: is it really a surprise? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a>, <a href="/search/?searchtype=author&query=Bouchy%2C+F">F. Bouchy</a>, <a href="/search/?searchtype=author&query=Bruntt%2C+H">H. Bruntt</a>, <a href="/search/?searchtype=author&query=Butler%2C+R+P">R. P. Butler</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Christensen-Dalsgaard%2C+J">J. Christensen-Dalsgaard</a>, <a href="/search/?searchtype=author&query=Frandsen%2C+S">S. Frandsen</a>, <a href="/search/?searchtype=author&query=Lebrun%2C+J+-">J. -C. Lebrun</a>, <a href="/search/?searchtype=author&query=Martic%2C+M">M. Martic</a>, <a href="/search/?searchtype=author&query=Schou%2C+J">J. Schou</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="astro-ph/0501662v1-abstract-short" style="display: inline;"> We argue that the non-detection of oscillations in Procyon by the MOST satellite reported by Matthews et al. (2004) is fully consistent with published ground-based velocity observations of this star. We also examine the claims that the MOST observations represent the best photometric precision so far reported in the literature by about an order of magnitude and are the most sensitive data set fo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0501662v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0501662v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0501662v1-abstract-full" style="display: none;"> We argue that the non-detection of oscillations in Procyon by the MOST satellite reported by Matthews et al. (2004) is fully consistent with published ground-based velocity observations of this star. We also examine the claims that the MOST observations represent the best photometric precision so far reported in the literature by about an order of magnitude and are the most sensitive data set for asteroseismology available for any star other than the Sun. These statements are not correct, with the most notable exceptions being observations of oscillations in alpha Cen A that are far superior. We further disagree that the hump of excess power seen repeatedly from velocity observations of Procyon can be explained as an artefact caused by gaps in the data. The MOST observations failed to reveal oscillations clearly because their noise level is too high, possibly from scattered Earthlight in the instrument. We did find an excess of strong peaks in the MOST amplitude spectrum that is inconsistent with a simple noise source such as granulation, and may perhaps indicate oscillations at roughly the expected level. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0501662v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0501662v1-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, 2005; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2005. </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, accepted for publication in A&A 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/astro-ph/0405127">arXiv:astro-ph/0405127</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0405127">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0405127">ps</a>, <a href="https://arxiv.org/format/astro-ph/0405127">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1086/426704">10.1086/426704 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Altair: The Brightest Delta Scuti Star </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">D. L. Buzasi</a>, <a href="/search/?searchtype=author&query=Bruntt%2C+H">H. Bruntt</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">T. R. Bedding</a>, <a href="/search/?searchtype=author&query=Retter%2C+A">A. Retter</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">H. Kjeldsen</a>, <a href="/search/?searchtype=author&query=Preston%2C+H+L">H. L. Preston</a>, <a href="/search/?searchtype=author&query=Mandeville%2C+W+J">W. J. Mandeville</a>, <a href="/search/?searchtype=author&query=Catanzarite%2C+J">J. Catanzarite</a>, <a href="/search/?searchtype=author&query=Conrow%2C+T">T. Conrow</a>, <a href="/search/?searchtype=author&query=Laher%2C+R">R. Laher</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="astro-ph/0405127v1-abstract-short" style="display: inline;"> We present an analysis of observations of the bright star Altair (alpha Aql) obtained using the star camera on the Wide-Field Infrared Explorer (WIRE) satellite. Although Altair lies within the delta Scuti instability strip, previous observations have not revealed the presence of oscillations. However, the WIRE observations show Altair to be a low-amplitude (Delta m < 1 ppt) delta Scuti star wit… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0405127v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0405127v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0405127v1-abstract-full" style="display: none;"> We present an analysis of observations of the bright star Altair (alpha Aql) obtained using the star camera on the Wide-Field Infrared Explorer (WIRE) satellite. Although Altair lies within the delta Scuti instability strip, previous observations have not revealed the presence of oscillations. However, the WIRE observations show Altair to be a low-amplitude (Delta m < 1 ppt) delta Scuti star with at least 7 modes present. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0405127v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0405127v1-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 May, 2004; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2004. </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, 6 figure files (only 5 figures), 2 tables</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astrophys.J. 619 (2005) 1072-1076 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0312218">arXiv:astro-ph/0312218</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0312218">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0312218">ps</a>, <a href="https://arxiv.org/format/astro-ph/0312218">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1086/381889">10.1086/381889 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Tight Upper Limit on Oscillations in the Ap star Epsilon Ursae Majoris from WIRE Photometry </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Retter%2C+A">Alon Retter</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">Hans Kjeldsen</a>, <a href="/search/?searchtype=author&query=Kiss%2C+L+L">Laszlo L. Kiss</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="astro-ph/0312218v2-abstract-short" style="display: inline;"> Observations of Epsilon UMa obtained with the star tracker on the Wide Field Infrared Explorer (WIRE) satellite during a month in mid-2000 are analyzed. This is one of the most precise photometry of an Ap star. The amplitude spectrum is used to set an upper limit of 75 parts per million for the amplitude of stellar pulsations in this star unless it accidentally oscillates with a single mode at t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0312218v2-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0312218v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0312218v2-abstract-full" style="display: none;"> Observations of Epsilon UMa obtained with the star tracker on the Wide Field Infrared Explorer (WIRE) satellite during a month in mid-2000 are analyzed. This is one of the most precise photometry of an Ap star. The amplitude spectrum is used to set an upper limit of 75 parts per million for the amplitude of stellar pulsations in this star unless it accidentally oscillates with a single mode at the satellite orbit, its harmonics or their one day aliases. This is the tightest limit put on the amplitude of oscillations in an Ap star. As the rotation period of Epsilon UMa is relatively short (5.1 d), it cannot be argued that the observations were made at a wrong rotational phase. Our results thus support the idea that some Ap stars do not pulsate at all. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0312218v2-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0312218v2-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> 9 December, 2003; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 December, 2003; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2003. </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, 4 figures, 2 style files, accepted for publication in ApJL</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astrophys.J. 601 (2004) L95-L98 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0310319">arXiv:astro-ph/0310319</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0310319">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0310319">ps</a>, <a href="https://arxiv.org/format/astro-ph/0310319">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> </div> </div> <p class="title is-5 mathjax"> Stellar Coronal Spectroscopy with the Chandra HETGS </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Huenemoerder%2C+D+P">David P. Huenemoerder</a>, <a href="/search/?searchtype=author&query=Boroson%2C+B">Bram Boroson</a>, <a href="/search/?searchtype=author&query=Schulz%2C+N+S">Norbert S. Schulz</a>, <a href="/search/?searchtype=author&query=Canizares%2C+C+R">Claude R. Canizares</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Preston%2C+H+L">Heather L. Preston</a>, <a href="/search/?searchtype=author&query=Kastner%2C+J+H">Joel H. Kastner</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="astro-ph/0310319v1-abstract-short" style="display: inline;"> Spectroscopy with the Chandra High Energy Transmission Grating Spectrometer provides details on X-ray emission and activity from young and cool stars through resolution of emission lines from a variety of ions. We are beginning to see trends in activity regarding abundances, emission measures, and variability. Here we contrast spectra of TV Crt, a weak-lined T Tauri star, with TW Hya, a Classica… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0310319v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0310319v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0310319v1-abstract-full" style="display: none;"> Spectroscopy with the Chandra High Energy Transmission Grating Spectrometer provides details on X-ray emission and activity from young and cool stars through resolution of emission lines from a variety of ions. We are beginning to see trends in activity regarding abundances, emission measures, and variability. Here we contrast spectra of TV Crt, a weak-lined T Tauri star, with TW Hya, a Classical T Tauri star. TV Crt has a spectrum more like magnetic activity driven coronae, relative to the TW Hya spectrum, which we have interpreted as due to accretion-produced X-rays. We have also observed the long period system, IM Pegasi to search for rotational modulation, and to compare activity in a long period active binary to shorter period systems and to the pre-main sequence stars. We detected no rotational modulation, but did see long-duration flares. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0310319v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0310319v1-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> 11 October, 2003; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2003. </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">5 pages, 2 figures; to be published in IAU Symposium 219: "Stars as Suns: Activity, Evolution, Planets" (Ed. A. Dupree and A. O. Benz)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0308424">arXiv:astro-ph/0308424</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0308424">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0308424">ps</a>, <a href="https://arxiv.org/format/astro-ph/0308424">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</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/10.1086/379210">10.1086/379210 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Erratum: "Oscillations in Arcturus from WIRE photometry" (ApJ, 591, L151 [2003]) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Retter%2C+A">Alon Retter</a>, <a href="/search/?searchtype=author&query=Bedding%2C+T+R">Timothy R. Bedding</a>, <a href="/search/?searchtype=author&query=Buzasi%2C+D+L">Derek L. Buzasi</a>, <a href="/search/?searchtype=author&query=Kjeldsen%2C+H">Hans Kjeldsen</a>, <a href="/search/?searchtype=author&query=Kiss%2C+L+L">L谩szl贸 L. Kiss</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="astro-ph/0308424v1-abstract-short" style="display: inline;"> The value of the mode lifetime given in the first paragraph of the Discussion should be divided by 2pi and is therefore 2.0 days rather than 13 days. </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0308424v1-abstract-full" style="display: none;"> The value of the mode lifetime given in the first paragraph of the Discussion should be divided by 2pi and is therefore 2.0 days rather than 13 days. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0308424v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0308424v1-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, 2003; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2003. </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">2 pages, 1 Latex file, ApJL, accepted</span> </p> </li> </ol> <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=Buzasi%2C+D+L&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Buzasi%2C+D+L&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Buzasi%2C+D+L&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <div 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