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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <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/2403.09847">arXiv:2403.09847</a> <span> [<a href="https://arxiv.org/pdf/2403.09847">pdf</a>, <a href="https://arxiv.org/format/2403.09847">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> <span class="tag is-small is-grey 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="Artificial Intelligence">cs.AI</span> </div> </div> <p class="title is-5 mathjax"> Forecasting Geoffective Events from Solar Wind Data and Evaluating the Most Predictive Features through Machine Learning Approaches </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Guastavino%2C+S">Sabrina Guastavino</a>, <a href="/search/astro-ph?searchtype=author&query=Bahamazava%2C+K">Katsiaryna Bahamazava</a>, <a href="/search/astro-ph?searchtype=author&query=Perracchione%2C+E">Emma Perracchione</a>, <a href="/search/astro-ph?searchtype=author&query=Camattari%2C+F">Fabiana Camattari</a>, <a href="/search/astro-ph?searchtype=author&query=Audone%2C+G">Gianluca Audone</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">Daniele Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">Gianalfredo Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Piana%2C+M">Michele Piana</a>, <a href="/search/astro-ph?searchtype=author&query=Massone%2C+A+M">Anna Maria Massone</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="2403.09847v1-abstract-short" style="display: inline;"> This study addresses the prediction of geomagnetic disturbances by exploiting machine learning techniques. Specifically, the Long-Short Term Memory recurrent neural network, which is particularly suited for application over long time series, is employed in the analysis of in-situ measurements of solar wind plasma and magnetic field acquired over more than one solar cycle, from $2005$ to $2019$, at… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.09847v1-abstract-full').style.display = 'inline'; document.getElementById('2403.09847v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.09847v1-abstract-full" style="display: none;"> This study addresses the prediction of geomagnetic disturbances by exploiting machine learning techniques. Specifically, the Long-Short Term Memory recurrent neural network, which is particularly suited for application over long time series, is employed in the analysis of in-situ measurements of solar wind plasma and magnetic field acquired over more than one solar cycle, from $2005$ to $2019$, at the Lagrangian point L$1$. The problem is approached as a binary classification aiming to predict one hour in advance a decrease in the SYM-H geomagnetic activity index below the threshold of $-50$ nT, which is generally regarded as indicative of magnetospheric perturbations. The strong class imbalance issue is tackled by using an appropriate loss function tailored to optimize appropriate skill scores in the training phase of the neural network. Beside classical skill scores, value-weighted skill scores are then employed to evaluate predictions, suitable in the study of problems, such as the one faced here, characterized by strong temporal variability. For the first time, the content of magnetic helicity and energy carried by solar transients, associated with their detection and likelihood of geo-effectiveness, were considered as input features of the network architecture. Their predictive capabilities are demonstrated through a correlation-driven feature selection method to rank the most relevant characteristics involved in the neural network prediction model. The optimal performance of the adopted neural network in properly forecasting the onset of geomagnetic storms, which is a crucial point for giving real warnings in an operational setting, is finally showed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.09847v1-abstract-full').style.display = 'none'; document.getElementById('2403.09847v1-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 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">MSC Class:</span> 85-08; 68T07; 68T05 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.01899">arXiv:2312.01899</a> <span> [<a href="https://arxiv.org/pdf/2312.01899">pdf</a>, <a href="https://arxiv.org/format/2312.01899">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"> Eruptive events with exceptionally bright emission in HI Ly-alpha observed by the Metis coronagraph </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Russano%2C+G">G. Russano</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Y. De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Teriaca%2C+L">L. Teriaca</a>, <a href="/search/astro-ph?searchtype=author&query=Uslenghi%2C+M">M. Uslenghi</a>, <a href="/search/astro-ph?searchtype=author&query=Giordano%2C+S">S. Giordano</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">D. Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">P. Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=%C4%8D%2C+S+J+%C4%8D">S. Jej 膷i 膷</a>, <a href="/search/astro-ph?searchtype=author&query=Abbo%2C+L">L. Abbo</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Burtovoi%2C+A">A. Burtovoi</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G+E">G. E. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">F. Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Guglielmino%2C+S">S. Guglielmino</a>, <a href="/search/astro-ph?searchtype=author&query=Jerse%2C+G">G. Jerse</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">F. Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">A. Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">G. Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">M. Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Romano%2C+P">P. Romano</a>, <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">C. Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Zangrilli%2C+L">L. Zangrilli</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</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="2312.01899v1-abstract-short" style="display: inline;"> Metis, the coronagraph on board Solar Orbiter, provides for the first time coronagraphic imaging in the ultraviolet HI Ly-alpha line and, simultaneously, in polarized visible light, thus providing a host of information on the properties of CMEs and solar eruptions like their overall dynamics, time evolution, mass content, and outflow propagation velocity in the expanding corona. We analyzed in thi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.01899v1-abstract-full').style.display = 'inline'; document.getElementById('2312.01899v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.01899v1-abstract-full" style="display: none;"> Metis, the coronagraph on board Solar Orbiter, provides for the first time coronagraphic imaging in the ultraviolet HI Ly-alpha line and, simultaneously, in polarized visible light, thus providing a host of information on the properties of CMEs and solar eruptions like their overall dynamics, time evolution, mass content, and outflow propagation velocity in the expanding corona. We analyzed in this work six CMEs observed by Metis between April and October 2021, which are characterized by a very strong HI Ly-alpha emission. We studied in particular the morphology, kinematics, and the temporal and radial evolution of the emission of such events, focusing on the brightest UV features. The kinematics of the eruptive events under consideration were studied by determining the height-time profiles of the brightest parts on the Metis plane of the sky. Furthermore, the 3D position in the heliosphere of the CMEs were determined by employing co-temporal images from two other coronagraphs: LASCO/C2 onboard SOHO, and COR2 onboard STEREO-A. Finally, the radiometrically calibrated Metis images of the bright UV features were analyzed to provide estimates of their volume and density. From the kinematics and radiometric analyses, we obtained indications of the temperatures of the bright UV cores of these events. The analysis of these strong UV-emitting features associated with coronal mass ejections demonstrates the capabilities of the current constellation of space coronagraphs, Metis, LASCO/C2, and COR2, in providing a complete characterization of the structure and dynamics of eruptive events in their propagation phase from their inception up to several solar radii. Furthermore, we show how the unique capabilities of the Metis instrument to observe these events in both HI Ly-alpha line and polarized VL radiation allow plasma diagnostics on the thermal state of these events. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.01899v1-abstract-full').style.display = 'none'; document.getElementById('2312.01899v1-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 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">26 pages, 26 figures, 2 appendices</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">MSC Class:</span> 85-02 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.10819">arXiv:2306.10819</a> <span> [<a href="https://arxiv.org/pdf/2306.10819">pdf</a>, <a href="https://arxiv.org/format/2306.10819">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="Space Physics">physics.space-ph</span> </div> </div> <p class="title is-5 mathjax"> Coronal Heating Rate in the Slow Solar Wind </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">Daniele Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">Marco Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Velli%2C+M">Marco Velli</a>, <a href="/search/astro-ph?searchtype=author&query=Zank%2C+G+P">Gary P. Zank</a>, <a href="/search/astro-ph?searchtype=author&query=Adhikari%2C+L">Laxman Adhikari</a>, <a href="/search/astro-ph?searchtype=author&query=Downs%2C+C">Cooper Downs</a>, <a href="/search/astro-ph?searchtype=author&query=Burtovoi%2C+A">Aleksandr Burtovoi</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">Daniele Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+L">Lingling Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">Alessandro Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Shi%2C+C">Chen Shi</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Yara De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Abbo%2C+L">Lucia Abbo</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">Federica Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Jerse%2C+G">Giovanna Jerse</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">Federico Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">Gianalfredo Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">Maurizio Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Russano%2C+G">Giuliana Russano</a>, <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">Clementina Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">Vania Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Grimani%2C+C">Catia Grimani</a> , et al. (37 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="2306.10819v1-abstract-short" style="display: inline;"> This Letter reports the first observational estimate of the heating rate in the slowly expanding solar corona. The analysis exploits the simultaneous remote and local observations of the same coronal plasma volume with the Solar Orbiter/Metis and the Parker Solar Probe instruments, respectively, and relies on the basic solar wind magnetohydrodynamic equations. As expected, energy losses are a mino… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10819v1-abstract-full').style.display = 'inline'; document.getElementById('2306.10819v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.10819v1-abstract-full" style="display: none;"> This Letter reports the first observational estimate of the heating rate in the slowly expanding solar corona. The analysis exploits the simultaneous remote and local observations of the same coronal plasma volume with the Solar Orbiter/Metis and the Parker Solar Probe instruments, respectively, and relies on the basic solar wind magnetohydrodynamic equations. As expected, energy losses are a minor fraction of the solar wind energy flux, since most of the energy dissipation that feeds the heating and acceleration of the coronal flow occurs much closer to the Sun than the heights probed in the present study, which range from 6.3 to 13.3 solar radii. The energy deposited to the supersonic wind is then used to explain the observed slight residual wind acceleration and to maintain the plasma in a non-adiabatic state. As derived in the Wentzel-Kramers-Brillouin limit, the present energy transfer rate estimates provide a lower limit, which can be very useful in refining the turbulence-based modeling of coronal heating and subsequent solar wind acceleration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10819v1-abstract-full').style.display = 'none'; document.getElementById('2306.10819v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.10057">arXiv:2305.10057</a> <span> [<a href="https://arxiv.org/pdf/2305.10057">pdf</a>, <a href="https://arxiv.org/format/2305.10057">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> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> </div> </div> <p class="title is-5 mathjax"> Physics-driven machine learning for the prediction of coronal mass ejections' travel times </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Guastavino%2C+S">Sabrina Guastavino</a>, <a href="/search/astro-ph?searchtype=author&query=Candiani%2C+V">Valentina Candiani</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">Alessandro Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Marchetti%2C+F">Francesco Marchetti</a>, <a href="/search/astro-ph?searchtype=author&query=Benvenuto%2C+F">Federico Benvenuto</a>, <a href="/search/astro-ph?searchtype=author&query=Massone%2C+A+M">Anna Maria Massone</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">Daniele Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Piana%2C+M">Michele Piana</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="2305.10057v1-abstract-short" style="display: inline;"> Coronal Mass Ejections (CMEs) correspond to dramatic expulsions of plasma and magnetic field from the solar corona into the heliosphere. CMEs are scientifically relevant because they are involved in the physical mechanisms characterizing the active Sun. However, more recently CMEs have attracted attention for their impact on space weather, as they are correlated to geomagnetic storms and may induc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.10057v1-abstract-full').style.display = 'inline'; document.getElementById('2305.10057v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.10057v1-abstract-full" style="display: none;"> Coronal Mass Ejections (CMEs) correspond to dramatic expulsions of plasma and magnetic field from the solar corona into the heliosphere. CMEs are scientifically relevant because they are involved in the physical mechanisms characterizing the active Sun. However, more recently CMEs have attracted attention for their impact on space weather, as they are correlated to geomagnetic storms and may induce the generation of Solar Energetic Particles streams. In this space weather framework, the present paper introduces a physics-driven artificial intelligence (AI) approach to the prediction of CMEs travel time, in which the deterministic drag-based model is exploited to improve the training phase of a cascade of two neural networks fed with both remote sensing and in-situ data. This study shows that the use of physical information in the AI architecture significantly improves both the accuracy and the robustness of the travel time prediction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.10057v1-abstract-full').style.display = 'none'; document.getElementById('2305.10057v1-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 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">MSC Class:</span> 68T07; 85-08; 65K10 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.10545">arXiv:2302.10545</a> <span> [<a href="https://arxiv.org/pdf/2302.10545">pdf</a>, <a href="https://arxiv.org/format/2302.10545">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/acb693">10.3847/1538-4357/acb693 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Does Turbulence along the Coronal Current Sheet Drive Ion Cyclotron Waves? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">Daniele Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Zank%2C+G+P">Gary P. Zank</a>, <a href="/search/astro-ph?searchtype=author&query=Adhikari%2C+L">Laxman Adhikari</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+L">Lingling Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">Ester Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Stangalini%2C+M">Marco Stangalini</a>, <a href="/search/astro-ph?searchtype=author&query=Grimani%2C+C">Catia Grimani</a>, <a href="/search/astro-ph?searchtype=author&query=Sorriso-Valvo%2C+L">Luca Sorriso-Valvo</a>, <a href="/search/astro-ph?searchtype=author&query=Verscharen%2C+D">Daniel Verscharen</a>, <a href="/search/astro-ph?searchtype=author&query=Marino%2C+R">Raffaele Marino</a>, <a href="/search/astro-ph?searchtype=author&query=Giordano%2C+S">Silvio Giordano</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Amicis%2C+R">Raffaella D'Amicis</a>, <a href="/search/astro-ph?searchtype=author&query=Perrone%2C+D">Denise Perrone</a>, <a href="/search/astro-ph?searchtype=author&query=Carbone%2C+F">Francesco Carbone</a>, <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">Alessandro Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+R">Roberto Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Zimbardo%2C+G">Gaetano Zimbardo</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">Marco Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">Vania Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">Petr Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=Moses%2C+J+D">John D. Moses</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">Giampiero Naletto</a> , et al. (10 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="2302.10545v1-abstract-short" style="display: inline;"> Evidence for the presence of ion cyclotron waves, driven by turbulence, at the boundaries of the current sheet is reported in this paper. By exploiting the full potential of the joint observations performed by Parker Solar Probe and the Metis coronagraph on board Solar Orbiter, local measurements of the solar wind can be linked with the large-scale structures of the solar corona. The results sugge… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.10545v1-abstract-full').style.display = 'inline'; document.getElementById('2302.10545v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.10545v1-abstract-full" style="display: none;"> Evidence for the presence of ion cyclotron waves, driven by turbulence, at the boundaries of the current sheet is reported in this paper. By exploiting the full potential of the joint observations performed by Parker Solar Probe and the Metis coronagraph on board Solar Orbiter, local measurements of the solar wind can be linked with the large-scale structures of the solar corona. The results suggest that the dynamics of the current sheet layers generates turbulence, which in turn creates a sufficiently strong temperature anisotropy to make the solar-wind plasma unstable to anisotropy-driven instabilities such as the Alfv茅n ion-cyclotron, mirror-mode, and firehose instabilities. The study of the polarization state of high-frequency magnetic fluctuations reveals that ion cyclotron waves are indeed present along the current sheet, thus linking the magnetic topology of the remotely imaged coronal source regions with the wave bursts observed in situ. The present results may allow improvement of state-of-the-art models based on the ion cyclotron mechanism, providing new insights into the processes involved in coronal heating. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.10545v1-abstract-full').style.display = 'none'; document.getElementById('2302.10545v1-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, 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">12 pages</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Astrophysical Journal, 2023 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.08385">arXiv:2302.08385</a> <span> [<a href="https://arxiv.org/pdf/2302.08385">pdf</a>, <a href="https://arxiv.org/format/2302.08385">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="Space Physics">physics.space-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/10.1063/5.0132824">10.1063/5.0132824 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Slow wind belt in the quiet solar corona </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">E. Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Downs%2C+C">C. Downs</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G+E">G. E. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">D. Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">D. Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Y. De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Frassetto%2C+F">F. Frassetto</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">F. Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">G. Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">G. Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">M. Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Stangalini%2C+M">M. Stangalini</a>, <a href="/search/astro-ph?searchtype=author&query=Teriaca%2C+L">L. Teriaca</a>, <a href="/search/astro-ph?searchtype=author&query=Uslenghi%2C+M">M. Uslenghi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.08385v1-abstract-short" style="display: inline;"> The slow solar wind belt in the quiet corona, observed with the Metis coronagraph on board Solar Orbiter on May 15, 2020, during the activity minimum of the cycle 24, in a field of view extending from 3.8 $R_\odot$ to 7.0 $R_\odot$, is formed by a slow and dense wind stream running along the coronal current sheet, accelerating in the radial direction and reaching at 6.8 $R_\odot$ a speed within 15… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.08385v1-abstract-full').style.display = 'inline'; document.getElementById('2302.08385v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.08385v1-abstract-full" style="display: none;"> The slow solar wind belt in the quiet corona, observed with the Metis coronagraph on board Solar Orbiter on May 15, 2020, during the activity minimum of the cycle 24, in a field of view extending from 3.8 $R_\odot$ to 7.0 $R_\odot$, is formed by a slow and dense wind stream running along the coronal current sheet, accelerating in the radial direction and reaching at 6.8 $R_\odot$ a speed within 150 km s$^{-1}$ and 190 km s$^{-1}$, depending on the assumptions on the velocity distribution of the neutral hydrogen atoms in the coronal plasma. The slow stream is separated by thin regions of high velocity shear from faster streams, almost symmetric relative to the current sheet, with peak velocity within 175 km s$^{-1}$ and 230 km s$^{-1}$ at the same coronal level. The density-velocity structure of the slow wind zone is discussed in terms of the expansion factor of the open magnetic field lines that is known to be related to the speed of the quasi-steady solar wind, and in relation to the presence of a web of quasi separatrix layers, S-web, the potential sites of reconnection that release coronal plasma into the wind. The parameters characterizing the coronal magnetic field lines are derived from 3D MHD model calculations. The S-web is found to coincide with the latitudinal region where the slow wind is observed in the outer corona and is surrounded by thin layers of open field lines expanding in a non-monotonic way. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.08385v1-abstract-full').style.display = 'none'; document.getElementById('2302.08385v1-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> 16 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.07308">arXiv:2302.07308</a> <span> [<a href="https://arxiv.org/pdf/2302.07308">pdf</a>, <a href="https://arxiv.org/format/2302.07308">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/10.1051/0004-6361/202244069">10.1051/0004-6361/202244069 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> In-flight validation of Metis Visible-light Polarimeter Coronagraph on board Solar Orbiter </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">A. Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Casti%2C+M">M. Casti</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">G. Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Abbo%2C+L">L. Abbo</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Fabi%2C+M">M. Fabi</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">F. Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Jerse%2C+G">G. Jerse</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">F. Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Moses%2C+D">D. Moses</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">G. Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">G. Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">M. Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Russano%2C+G">G. Russano</a>, <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">C. Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">D. Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Stangalini%2C+M">M. Stangalini</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">D. Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Teriaca%2C+L">L. Teriaca</a>, <a href="/search/astro-ph?searchtype=author&query=Uslenghi%2C+M">M. Uslenghi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.07308v1-abstract-short" style="display: inline;"> Context. The Metis coronagraph is one of the remote-sensing instruments of the ESA/NASA Solar Orbiter mission. Metis is aimed at the study of the solar atmosphere and solar wind by simultaneously acquiring images of the solar corona at two different wavelengths; visible-light (VL) within a band ranging from 580 nm to 640 nm, and in the HI Ly-alpha 121.6 +/- 10 nm ultraviolet (UV) light. The visibl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.07308v1-abstract-full').style.display = 'inline'; document.getElementById('2302.07308v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.07308v1-abstract-full" style="display: none;"> Context. The Metis coronagraph is one of the remote-sensing instruments of the ESA/NASA Solar Orbiter mission. Metis is aimed at the study of the solar atmosphere and solar wind by simultaneously acquiring images of the solar corona at two different wavelengths; visible-light (VL) within a band ranging from 580 nm to 640 nm, and in the HI Ly-alpha 121.6 +/- 10 nm ultraviolet (UV) light. The visible-light channel includes a polarimeter with electro-optically modulating Liquid Crystal Variable Retarders (LCVRs) to measure the linearly polarized brightness of the K-corona to derive the electron density. Aims. In this paper, we present the first in-flight validation results of the Metis polarimetric channel together with a comparison to the on-ground calibrations. It is the validation of the first use in deep space (with hard radiation environment) of an electro-optical device: a liquid crystal-based polarimeter. Methods. We used the orientation of the K-corona's linear polarization vector during the spacecraft roll maneuvers for the in-flight calibration. Results. The first in-flight validation of the Metis coronagraph on-board Solar Orbiter shows a good agreement with the on-ground measurements. It confirms the expected visible-light channel polarimetric performance. A final comparison between the first pB obtained by Metis with the polarized brightness (pB) obtained by the space-based coronagraph LASCO and the ground-based coronagraph KCor shows the consistency of the Metis calibrated results. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.07308v1-abstract-full').style.display = 'none'; document.getElementById('2302.07308v1-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 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">8 pages, 13 figures, 3 tables, paper</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 672, A14 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.07647">arXiv:2301.07647</a> <span> [<a href="https://arxiv.org/pdf/2301.07647">pdf</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"> Solaris: A Focused Solar Polar Discovery-class Mission to achieve the Highest Priority Heliophysics Science Now </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Hassler%2C+D+M">Donald M. Hassler</a>, <a href="/search/astro-ph?searchtype=author&query=Gibson%2C+S+E">Sarah E Gibson</a>, <a href="/search/astro-ph?searchtype=author&query=Newmark%2C+J+S">Jeffrey S Newmark</a>, <a href="/search/astro-ph?searchtype=author&query=Featherstone%2C+N+A">Nicholas A. Featherstone</a>, <a href="/search/astro-ph?searchtype=author&query=Upton%2C+L">Lisa Upton</a>, <a href="/search/astro-ph?searchtype=author&query=Viall%2C+N+M">Nicholeen M Viall</a>, <a href="/search/astro-ph?searchtype=author&query=Hoeksema%2C+J+T">J Todd Hoeksema</a>, <a href="/search/astro-ph?searchtype=author&query=Auchere%2C+F">Frederic Auchere</a>, <a href="/search/astro-ph?searchtype=author&query=Birch%2C+A">Aaron Birch</a>, <a href="/search/astro-ph?searchtype=author&query=Braun%2C+D">Doug Braun</a>, <a href="/search/astro-ph?searchtype=author&query=Charbonneau%2C+P">Paul Charbonneau</a>, <a href="/search/astro-ph?searchtype=author&query=Colannino%2C+R">Robin Colannino</a>, <a href="/search/astro-ph?searchtype=author&query=DeForest%2C+C">Craig DeForest</a>, <a href="/search/astro-ph?searchtype=author&query=Dikpati%2C+M">Mausumi Dikpati</a>, <a href="/search/astro-ph?searchtype=author&query=Downs%2C+C">Cooper Downs</a>, <a href="/search/astro-ph?searchtype=author&query=Duncan%2C+N">Nicole Duncan</a>, <a href="/search/astro-ph?searchtype=author&query=Elliott%2C+H+A">Heather Alison Elliott</a>, <a href="/search/astro-ph?searchtype=author&query=Fan%2C+Y">Yuhong Fan</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Gizon%2C+L">Laurent Gizon</a>, <a href="/search/astro-ph?searchtype=author&query=Gosain%2C+S">Sanjay Gosain</a>, <a href="/search/astro-ph?searchtype=author&query=Harra%2C+L">Louise Harra</a>, <a href="/search/astro-ph?searchtype=author&query=Hindman%2C+B">Brad Hindman</a>, <a href="/search/astro-ph?searchtype=author&query=Berghmans%2C+D">David Berghmans</a>, <a href="/search/astro-ph?searchtype=author&query=Lepri%2C+S+T">Susan T Lepri</a> , et al. (11 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2301.07647v1-abstract-short" style="display: inline;"> Solaris is a transformative Solar Polar Discovery-class mission concept to address crucial outstanding questions that can only be answered from a polar vantage. Solaris will image the Sun's poles from ~75 degree latitude, providing new insight into the workings of the solar dynamo and the solar cycle, which are at the foundation of our understanding of space weather and space climate. Solaris will… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.07647v1-abstract-full').style.display = 'inline'; document.getElementById('2301.07647v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.07647v1-abstract-full" style="display: none;"> Solaris is a transformative Solar Polar Discovery-class mission concept to address crucial outstanding questions that can only be answered from a polar vantage. Solaris will image the Sun's poles from ~75 degree latitude, providing new insight into the workings of the solar dynamo and the solar cycle, which are at the foundation of our understanding of space weather and space climate. Solaris will also provide enabling observations for improved space weather research, modeling and prediction, revealing a unique, new view of the corona, coronal dynamics and CME eruptions from above. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.07647v1-abstract-full').style.display = 'none'; document.getElementById('2301.07647v1-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">This White Paper was submitted in 2022 to the United States National Academies Solar and Space Physics (Heliophysics) Decadal Survey</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.12994">arXiv:2211.12994</a> <span> [<a href="https://arxiv.org/pdf/2211.12994">pdf</a>, <a href="https://arxiv.org/format/2211.12994">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="Plasma Physics">physics.plasm-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-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/10.1051/0004-6361/202244535">10.1051/0004-6361/202244535 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Connecting Solar Orbiter remote-sensing observations and Parker Solar Probe in-situ measurements with a numerical MHD reconstruction of the Parker spiral </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Biondo%2C+R">Ruggero Biondo</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">Alessandro Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Pagano%2C+P">Paolo Pagano</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">Daniele Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Reale%2C+F">Fabio Reale</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">Marco Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">Ester Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">Vania Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Yara De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">Petr Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=Moses%2C+D">Daniel Moses</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">Giampiero Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">Gianalfredo Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">Daniele Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Stangalini%2C+M">Marco Stangalini</a>, <a href="/search/astro-ph?searchtype=author&query=Teriaca%2C+L">Luca Teriaca</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">Federico Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">Clementina Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Jerse%2C+G">Giovanna Jerse</a>, <a href="/search/astro-ph?searchtype=author&query=Uslenghi%2C+M">Michela Uslenghi</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">Maurizio Pancrazzi</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="2211.12994v1-abstract-short" style="display: inline;"> As a key feature, NASA's Parker Solar Probe (PSP) and ESA-NASA's Solar Orbiter (SO) missions cooperate to trace solar wind and transients from their sources on the Sun to the inner interplanetary space. The goal of this work is to accurately reconstruct the interplanetary Parker spiral and the connection between coronal features observed remotely by the Metis coronagraph on-board SO and those dete… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.12994v1-abstract-full').style.display = 'inline'; document.getElementById('2211.12994v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.12994v1-abstract-full" style="display: none;"> As a key feature, NASA's Parker Solar Probe (PSP) and ESA-NASA's Solar Orbiter (SO) missions cooperate to trace solar wind and transients from their sources on the Sun to the inner interplanetary space. The goal of this work is to accurately reconstruct the interplanetary Parker spiral and the connection between coronal features observed remotely by the Metis coronagraph on-board SO and those detected in situ by PSP at the time of the first PSP-SO quadrature of January 2021. We use the Reverse In-situ and MHD Approach (RIMAP), a hybrid analytical-numerical method performing data-driven reconstructions of the Parker spiral. RIMAP solves the MHD equations on the equatorial plane with the PLUTO code, using the measurements collected by PSP between 0.1 and 0.2 AU as boundary conditions. Our reconstruction connects density and wind speed measurements provided by Metis (3-6 solar radii) to those acquired by PSP (21.5 solar radii) along a single streamline. The capability of our MHD model to connect the inner corona observed by Metis and the super Alfv茅nic wind measured by PSP, not only confirms the research pathways provided by multi-spacecraft observations, but also the validity and accuracy of RIMAP reconstructions as a possible test bench to verify models of transient phenomena propagating across the heliosphere, such as coronal mass ejections, solar energetic particles and solar wind switchbacks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.12994v1-abstract-full').style.display = 'none'; document.getElementById('2211.12994v1-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 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">Astronomy & Astrophysics, Solar Orbiter First Results (Nominal Mission Phase), (in press) DOI: 10.1051/0004-6361/202244535</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 668, A144 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.03090">arXiv:2206.03090</a> <span> [<a href="https://arxiv.org/pdf/2206.03090">pdf</a>, <a href="https://arxiv.org/format/2206.03090">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/ac8104">10.3847/2041-8213/ac8104 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of Magnetic Switchback in the Solar Corona </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">Daniele Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Zank%2C+G+P">Gary P. Zank</a>, <a href="/search/astro-ph?searchtype=author&query=Stangalini%2C+M">Marco Stangalini</a>, <a href="/search/astro-ph?searchtype=author&query=Downs%2C+C">Cooper Downs</a>, <a href="/search/astro-ph?searchtype=author&query=Liang%2C+H">Haoming Liang</a>, <a href="/search/astro-ph?searchtype=author&query=Nakanotani%2C+M">Masaru Nakanotani</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">Ester Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Sorriso-Valvo%2C+L">Luca Sorriso-Valvo</a>, <a href="/search/astro-ph?searchtype=author&query=Adhikari%2C+L">Laxman Adhikari</a>, <a href="/search/astro-ph?searchtype=author&query=Zhao%2C+L">Lingling Zhao</a>, <a href="/search/astro-ph?searchtype=author&query=Marino%2C+R">Raffaele Marino</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Grimani%2C+C">Catia Grimani</a>, <a href="/search/astro-ph?searchtype=author&query=Fabi%2C+M">Michele Fabi</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Amicis%2C+R">Raffaella D'Amicis</a>, <a href="/search/astro-ph?searchtype=author&query=Perrone%2C+D">Denise Perrone</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+R">Roberto Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Carbone%2C+F">Francesco Carbone</a>, <a href="/search/astro-ph?searchtype=author&query=Mancuso%2C+S">Salvatore Mancuso</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">Marco Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">Vania Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">Petr Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=Moses%2C+J+D">John D. Moses</a> , et al. (27 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2206.03090v2-abstract-short" style="display: inline;"> Switchbacks are sudden, large radial deflections of the solar wind magnetic field, widely revealed in interplanetary space by the Parker Solar Probe. The switchbacks' formation mechanism and sources are still unresolved, although candidate mechanisms include Alfv茅nic turbulence, shear-driven Kelvin-Helmholtz instabilities, interchange reconnection, and geometrical effects related to the Parker spi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.03090v2-abstract-full').style.display = 'inline'; document.getElementById('2206.03090v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.03090v2-abstract-full" style="display: none;"> Switchbacks are sudden, large radial deflections of the solar wind magnetic field, widely revealed in interplanetary space by the Parker Solar Probe. The switchbacks' formation mechanism and sources are still unresolved, although candidate mechanisms include Alfv茅nic turbulence, shear-driven Kelvin-Helmholtz instabilities, interchange reconnection, and geometrical effects related to the Parker spiral. This Letter presents observations from the Metis coronagraph onboard Solar Orbiter of a single large propagating S-shaped vortex, interpreted as first evidence of a switchback in the solar corona. It originated above an active region with the related loop system bounded by open-field regions to the East and West. Observations, modeling, and theory provide strong arguments in favor of the interchange reconnection origin of switchbacks. Metis measurements suggest that the initiation of the switchback may also be an indicator of the origin of slow solar wind. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.03090v2-abstract-full').style.display = 'none'; document.getElementById('2206.03090v2-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 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2202.10294">arXiv:2202.10294</a> <span> [<a href="https://arxiv.org/pdf/2202.10294">pdf</a>, <a href="https://arxiv.org/format/2202.10294">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="Space Physics">physics.space-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/10.1051/0004-6361/202243162">10.1051/0004-6361/202243162 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Coronal Mass Ejection followed by a prominence eruption and a plasma blob as observed by Solar Orbiter </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Mancuso%2C+S">S. Mancuso</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">D. Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Mierla%2C+M">M. Mierla</a>, <a href="/search/astro-ph?searchtype=author&query=Berghmans%2C+D">D. Berghmans</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Huys%2C+E">E. D'Huys</a>, <a href="/search/astro-ph?searchtype=author&query=Zhukov%2C+A+N">A. N. Zhukov</a>, <a href="/search/astro-ph?searchtype=author&query=Talpeanu%2C+D+-">D. -C. Talpeanu</a>, <a href="/search/astro-ph?searchtype=author&query=Colaninno%2C+R">R. Colaninno</a>, <a href="/search/astro-ph?searchtype=author&query=Hess%2C+P">P. Hess</a>, <a href="/search/astro-ph?searchtype=author&query=Koza%2C+J">J. Koza</a>, <a href="/search/astro-ph?searchtype=author&query=Jejcic%2C+S">S. Jejcic</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">P. Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">E. Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">F. Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Jerse%2C+G">G. Jerse</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">F. Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">G. Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">G. Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">M. Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a> , et al. (4 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2202.10294v1-abstract-short" style="display: inline;"> On February 12, 2021 two subsequent eruptions occurred above the West limb, as seen along the Sun-Earth line. The first event was a typical slow Coronal Mass Ejection (CME), followed $\sim 7$ hours later by a smaller and collimated prominence eruption, originating Southward with respect to the CME, followed by a plasma blob. These events were observed not only by SOHO and STEREO-A missions, but al… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.10294v1-abstract-full').style.display = 'inline'; document.getElementById('2202.10294v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2202.10294v1-abstract-full" style="display: none;"> On February 12, 2021 two subsequent eruptions occurred above the West limb, as seen along the Sun-Earth line. The first event was a typical slow Coronal Mass Ejection (CME), followed $\sim 7$ hours later by a smaller and collimated prominence eruption, originating Southward with respect to the CME, followed by a plasma blob. These events were observed not only by SOHO and STEREO-A missions, but also by the suite of remote sensing instruments on-board Solar Orbiter (SolO). This work shows how data acquired by the Full Sun Imager (FSI), Metis coronagraph, and Heliospheric Imager (SoloHI) from the SolO perspective can be combined to study the eruptions and the different source regions. Moreover, we show how Metis data can be analyzed to provide new information about solar eruptions. Different 3D reconstruction methods were applied to the data acquired by different spacecraft including remote sensing instruments on-board SolO. Images acquired by both Metis channels in the Visible Light (VL) and H I Lyman$-伪$ line (UV) were combined to derive physical information on the expanding plasma. The polarization ratio technique was also applied for the first time to the Metis images acquired in the VL channel. The two eruptions were followed in 3D from their source region to their expansion in the intermediate corona. Thanks to the combination of VL and UV Metis data, the formation of a post-CME Current Sheet (CS) was followed for the first time in the intermediate corona. The plasma temperature gradient across a post-CME blob propagating along the CS was also measured for the first time. Application of the polarization ratio technique to Metis data shows that, thanks to the combination of four different polarization measurements, the errors are reduced by $\sim 5-7$\%, thus better constraining the 3D distribution of plasma. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.10294v1-abstract-full').style.display = 'none'; document.getElementById('2202.10294v1-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 14 figures, accepted for publication on A&A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 665, A7 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.00660">arXiv:2201.00660</a> <span> [<a href="https://arxiv.org/pdf/2201.00660">pdf</a>, <a href="https://arxiv.org/format/2201.00660">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/10.1007/s11207-022-01958-x">10.1007/s11207-022-01958-x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Sky Brightness evaluation at Concordia Station - Dome C, Antarctica for ground-based observations of the Solar Corona </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">Alessandro Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">Gerardo Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Massone%2C+G">Giuseppe Massone</a>, <a href="/search/astro-ph?searchtype=author&query=Zangrilli%2C+L">Luca Zangrilli</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">Gianalfredo Nicolini</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="2201.00660v2-abstract-short" style="display: inline;"> The evaluation of sky characteristics plays a fundamental role for many astrophysical experiments and ground-based observations. In solar physics, the main requirement for such observations is a very low sky brightness value, that is, less than one-millionth of the solar disk brightness. Few places match such requirement for ground-based, out-of-eclipse coronagraphic measurements. A candidate coro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.00660v2-abstract-full').style.display = 'inline'; document.getElementById('2201.00660v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.00660v2-abstract-full" style="display: none;"> The evaluation of sky characteristics plays a fundamental role for many astrophysical experiments and ground-based observations. In solar physics, the main requirement for such observations is a very low sky brightness value, that is, less than one-millionth of the solar disk brightness. Few places match such requirement for ground-based, out-of-eclipse coronagraphic measurements. A candidate coronagraphic site is the Dome C plateau in Antarctica. In this paper, we show the first results of the sky brightness measurements at Dome C with the Extreme Solar Coronagraphy Antarctic Program Experiment (ESCAPE) at Italian-French Concordia Station, on Dome C, Antarctica (3300 m) during the summer XXXIV and XXXV Expeditions of the "Italian Piano Nazionale Ricerche Antartiche" (PNRA). The sky brightness measurements were carried out with the internally-occulted Antarctic coronagraph - AntarctiCor. In optimal atmospheric conditions, the sky brightness of Dome C has reached values of the order of 1.0 to 0.7 millionth of of the solar disk brightness. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.00660v2-abstract-full').style.display = 'none'; document.getElementById('2201.00660v2-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 February, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2110.11031">arXiv:2110.11031</a> <span> [<a href="https://arxiv.org/pdf/2110.11031">pdf</a>, <a href="https://arxiv.org/format/2110.11031">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="Plasma Physics">physics.plasm-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-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/10.3847/2041-8213/ac282f">10.3847/2041-8213/ac282f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Exploring the Solar Wind from its Source on the Corona into the Inner Heliosphere during the First Solar Orbiter - Parker Solar Probe Quadrature </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">Daniele Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">Ester Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">Alessandro Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G+E">Giuseppe E. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Giordano%2C+S">Silvio Giordano</a>, <a href="/search/astro-ph?searchtype=author&query=Habbal%2C+S">Shadia Habbal</a>, <a href="/search/astro-ph?searchtype=author&query=Perrone%2C+D">Denise Perrone</a>, <a href="/search/astro-ph?searchtype=author&query=Pinto%2C+R+F">Rui F. Pinto</a>, <a href="/search/astro-ph?searchtype=author&query=Sorriso-Valvo%2C+L">Luca Sorriso-Valvo</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">Daniele Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Woodham%2C+L+D">Lloyd D. Woodham</a>, <a href="/search/astro-ph?searchtype=author&query=Zank%2C+G+P">Gary P. Zank</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">Marco Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Bale%2C+S+D">Stuart D. Bale</a>, <a href="/search/astro-ph?searchtype=author&query=Kasper%2C+J+C">Justin C. Kasper</a>, <a href="/search/astro-ph?searchtype=author&query=Auch%C3%A8re%2C+F">Fr茅d茅ric Auch猫re</a>, <a href="/search/astro-ph?searchtype=author&query=Bruno%2C+R">Roberto Bruno</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">Gerardo Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Case%2C+A+W">Anthony W. Case</a>, <a href="/search/astro-ph?searchtype=author&query=Casini%2C+C">Chiara Casini</a>, <a href="/search/astro-ph?searchtype=author&query=Casti%2C+M">Marta Casti</a>, <a href="/search/astro-ph?searchtype=author&query=Chioetto%2C+P">Paolo Chioetto</a> , et al. (46 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="2110.11031v1-abstract-short" style="display: inline;"> This Letter addresses the first Solar Orbiter (SO) -- Parker Solar Probe (PSP) quadrature, occurring on January 18, 2021, to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagation, the same plasma volume observed remotely in corona at altitudes between 3.5 and 6.3 solar radii above the solar limb with the Metis coronagraph on SO ca… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.11031v1-abstract-full').style.display = 'inline'; document.getElementById('2110.11031v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.11031v1-abstract-full" style="display: none;"> This Letter addresses the first Solar Orbiter (SO) -- Parker Solar Probe (PSP) quadrature, occurring on January 18, 2021, to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagation, the same plasma volume observed remotely in corona at altitudes between 3.5 and 6.3 solar radii above the solar limb with the Metis coronagraph on SO can be tracked to PSP, orbiting at 0.1 au, thus allowing the local properties of the solar wind to be linked to the coronal source region from where it originated. Thanks to the close approach of PSP to the Sun and the simultaneous Metis observation of the solar corona, the flow-aligned magnetic field and the bulk kinetic energy flux density can be empirically inferred along the coronal current sheet with an unprecedented accuracy, allowing in particular estimation of the Alfv茅n radius at 8.7 solar radii during the time of this event. This is thus the very first study of the same solar wind plasma as it expands from the sub-Alfv茅nic solar corona to just above the Alfv茅n surface. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.11031v1-abstract-full').style.display = 'none'; document.getElementById('2110.11031v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Telloni, D., Andretta, V., Antonucci, E., et al. 2021, ApJL, 920, L14 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.13344">arXiv:2106.13344</a> <span> [<a href="https://arxiv.org/pdf/2106.13344">pdf</a>, <a href="https://arxiv.org/format/2106.13344">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/10.1051/0004-6361/202140980">10.1051/0004-6361/202140980 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> First light observations of the solar wind in the outer corona with the Metis coronagraph </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">E. Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G+E">G. E. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Y. De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Downs%2C+C">C. Downs</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">P. Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">F. Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">A. Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">G. Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">G. Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">M. Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">C. Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">D. Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">D. Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Teriaca%2C+L">L. Teriaca</a>, <a href="/search/astro-ph?searchtype=author&query=Uslenghi%2C+M">M. Uslenghi</a>, <a href="/search/astro-ph?searchtype=author&query=Wang%2C+Y+M">Y. M. Wang</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">G. Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Casti%2C+M">M. Casti</a>, <a href="/search/astro-ph?searchtype=author&query=Fabi%2C+M">M. Fabi</a> , et al. (43 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="2106.13344v1-abstract-short" style="display: inline;"> The investigation of the wind in the solar corona initiated with the observations of the resonantly scattered UV emission of the coronal plasma obtained with UVCS-SOHO, designed to measure the wind outflow speed by applying the Doppler dimming diagnostics. Metis on Solar Orbiter complements the UVCS spectroscopic observations, performed during solar activity cycle 23, by simultaneously imaging the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.13344v1-abstract-full').style.display = 'inline'; document.getElementById('2106.13344v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.13344v1-abstract-full" style="display: none;"> The investigation of the wind in the solar corona initiated with the observations of the resonantly scattered UV emission of the coronal plasma obtained with UVCS-SOHO, designed to measure the wind outflow speed by applying the Doppler dimming diagnostics. Metis on Solar Orbiter complements the UVCS spectroscopic observations, performed during solar activity cycle 23, by simultaneously imaging the polarized visible light and the HI Ly-alpha corona in order to obtain high-spatial and temporal resolution maps of the outward velocity of the continuously expanding solar atmosphere. The Metis observations, on May 15, 2020, provide the first HI Ly-alpha images of the extended corona and the first instantaneous map of the speed of the coronal plasma outflows during the minimum of solar activity and allow us to identify the layer where the slow wind flow is observed. The polarized visible light (580-640 nm), and the UV HI Ly-alpha (121.6 nm) coronal emissions, obtained with the two Metis channels, are combined in order to measure the dimming of the UV emission relative to a static corona. This effect is caused by the outward motion of the coronal plasma along the direction of incidence of the chromospheric photons on the coronal neutral hydrogen. The plasma outflow velocity is then derived as a function of the measured Doppler dimming. The static corona UV emission is simulated on the basis of the plasma electron density inferred from the polarized visible light. This study leads to the identification, in the velocity maps of the solar corona, of the high-density layer about +/-10 deg wide, centered on the extension of a quiet equatorial streamer present at the East limb where the slowest wind flows at about (160 +/- 18) km/s from 4 Rs to 6 Rs. Beyond the boundaries of the high-density layer, the wind velocity rapidly increases, marking the transition between slow and fast wind in the corona. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.13344v1-abstract-full').style.display = 'none'; document.getElementById('2106.13344v1-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 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">Journal ref:</span> A&A, 2021, Forthcoming article </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.13700">arXiv:2104.13700</a> <span> [<a href="https://arxiv.org/pdf/2104.13700">pdf</a>, <a href="https://arxiv.org/format/2104.13700">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> </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/10.1051/0004-6361/202140930">10.1051/0004-6361/202140930 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Cosmic-ray flux predictions and observations for and with Metis on board Solar Orbiter </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Grimani%2C+C">C. Grimani</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Chioetto%2C+P">P. Chioetto</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Fabi%2C+M">M. Fabi</a>, <a href="/search/astro-ph?searchtype=author&query=Gissot%2C+S">S. Gissot</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">G. Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Persici%2C+A">A. Persici</a>, <a href="/search/astro-ph?searchtype=author&query=Plainaki%2C+C">C. Plainaki</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Sabbatini%2C+F">F. Sabbatini</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">D. Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Stangalini%2C+M">M. Stangalini</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">D. Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Uslenghi%2C+M">M. Uslenghi</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">E. Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">G. Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Capuano%2C+G">G. Capuano</a>, <a href="/search/astro-ph?searchtype=author&query=Casti%2C+M">M. Casti</a>, <a href="/search/astro-ph?searchtype=author&query=De+Leo%2C+Y">Y. De Leo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">F. Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Frassetto%2C+F">F. Frassetto</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">P. Heinzel</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="2104.13700v2-abstract-short" style="display: inline;"> The Metis coronagraph is one of the remote sensing instruments hosted on board the ESA/NASA Solar Orbiter mission. Metis is devoted to carry out the first simultaneous imaging of the solar corona in both visible light (VL) and ultraviolet (UV). High-energy particles penetrate spacecraft materials and may limit the performance of on-board instruments. A study of galactic cosmic-ray (GCR) tracks obs… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.13700v2-abstract-full').style.display = 'inline'; document.getElementById('2104.13700v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.13700v2-abstract-full" style="display: none;"> The Metis coronagraph is one of the remote sensing instruments hosted on board the ESA/NASA Solar Orbiter mission. Metis is devoted to carry out the first simultaneous imaging of the solar corona in both visible light (VL) and ultraviolet (UV). High-energy particles penetrate spacecraft materials and may limit the performance of on-board instruments. A study of galactic cosmic-ray (GCR) tracks observed in the first VL images gathered by Metis during the commissioning phase for a total of 60 seconds of exposure time is presented here. A similar analysis is planned for the UV channel. A prediction of the GCR flux up to hundreds of GeV is made here for the first part of the Solar Orbiter mission to study the Metis coronagraph performance. GCR model predictions are compared to observations gathered on board Solar Orbiter by the EPD/HET experiment in the range 10 MeV-100 MeV in the summer 2020 and with previous measurements. Estimated cosmic-ray fluxes above 70 MeV n$^{-1}$ have been also parameterized and used for Monte Carlo simulations aiming at reproducing the cosmic-ray track observations in the Metis coronagraph VL images. The same parameterizations can also be used to study the performance of other detectors. By comparing observations of cosmic-ray tracks in the Metis VL images with FLUKA Monte Carlo simulations of cosmic-ray interactions in the VL detector, it is found that cosmic rays fire a fraction of the order of 10$^{-4}$ of the whole image pixel sample. Therefore, cosmic rays do not affect sensibly the quality of Metis VL images. It is also found that the overall efficiency for cosmic-ray identification in the Metis VL images is approximately equal to the contribution of Z$>$2 particles. As a result, the Metis coronagraph may play the role of a proton monitor for long-term GCR variations during the overall mission duration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.13700v2-abstract-full').style.display = 'none'; document.getElementById('2104.13700v2-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 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 7 figures, accepted for publication on Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 656, A15 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.10876">arXiv:2104.10876</a> <span> [<a href="https://arxiv.org/pdf/2104.10876">pdf</a>, <a href="https://arxiv.org/ps/2104.10876">ps</a>, <a href="https://arxiv.org/format/2104.10876">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/10.1007/s10686-021-09769-x">10.1007/s10686-021-09769-x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A journey of exploration to the polar regions of a star: probing the solar poles and the heliosphere from high helio-latitude </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Harra%2C+L">Louise Harra</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Appourchaux%2C+T">Thierry Appourchaux</a>, <a href="/search/astro-ph?searchtype=author&query=Baudin%2C+F">Fr茅d茅ric Baudin</a>, <a href="/search/astro-ph?searchtype=author&query=Bellot-Rubio%2C+L">Luis Bellot-Rubio</a>, <a href="/search/astro-ph?searchtype=author&query=Birch%2C+A+C">Aaron C. Birch</a>, <a href="/search/astro-ph?searchtype=author&query=Boumier%2C+P">Patrick Boumier</a>, <a href="/search/astro-ph?searchtype=author&query=Cameron%2C+R+H">Robert H. Cameron</a>, <a href="/search/astro-ph?searchtype=author&query=Carlsson%2C+M">Matts Carlsson</a>, <a href="/search/astro-ph?searchtype=author&query=Corbard%2C+T">Thierry Corbard</a>, <a href="/search/astro-ph?searchtype=author&query=Davies%2C+J">Jackie Davies</a>, <a href="/search/astro-ph?searchtype=author&query=Fazakerley%2C+A">Andrew Fazakerley</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Finsterle%2C+W">Wolfgang Finsterle</a>, <a href="/search/astro-ph?searchtype=author&query=Gizon%2C+L">Laurent Gizon</a>, <a href="/search/astro-ph?searchtype=author&query=Harrison%2C+R">Richard Harrison</a>, <a href="/search/astro-ph?searchtype=author&query=Hassler%2C+D+M">Donald M. Hassler</a>, <a href="/search/astro-ph?searchtype=author&query=Leibacher%2C+J">John Leibacher</a>, <a href="/search/astro-ph?searchtype=author&query=Liewer%2C+P">Paulett Liewer</a>, <a href="/search/astro-ph?searchtype=author&query=MacDonald%2C+M">Malcolm MacDonald</a>, <a href="/search/astro-ph?searchtype=author&query=Maksimovic%2C+M">Milan Maksimovic</a>, <a href="/search/astro-ph?searchtype=author&query=Murphy%2C+N">Neil Murphy</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">Giampiero Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Nigro%2C+G">Giuseppina Nigro</a>, <a href="/search/astro-ph?searchtype=author&query=Owen%2C+C">Christopher Owen</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="2104.10876v1-abstract-short" style="display: inline;"> A mission to view the solar poles from high helio-latitudes (above 60$^\circ$) will build on the experience of Solar Orbiter as well as a long heritage of successful solar missions and instrumentation (e.g. SOHO \cite{SOHO}, STEREO \cite{stereo}, Hinode \cite{Hinode}, SDO \cite{SDO}), but will focus for the first time on the solar poles, enabling scientific investigations that cannot be done by an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.10876v1-abstract-full').style.display = 'inline'; document.getElementById('2104.10876v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.10876v1-abstract-full" style="display: none;"> A mission to view the solar poles from high helio-latitudes (above 60$^\circ$) will build on the experience of Solar Orbiter as well as a long heritage of successful solar missions and instrumentation (e.g. SOHO \cite{SOHO}, STEREO \cite{stereo}, Hinode \cite{Hinode}, SDO \cite{SDO}), but will focus for the first time on the solar poles, enabling scientific investigations that cannot be done by any other mission. One of the major mysteries of the Sun is the solar cycle. The activity cycle of the Sun drives the structure and behaviour of the heliosphere and is, of course, the driver of space weather. In addition, solar activity and variability provides fluctuating input into the Earth climate models, and these same physical processes are applicable to stellar systems hosting exoplanets. One of the main obstructions to understanding the solar cycle, and hence all solar activity, is our current lack of understanding of the polar regions. In this White Paper, submitted to the European Space Agency in response to the Voyage 2050 call, we describe a mission concept that aims to address this fundamental issue. In parallel, we recognise that viewing the Sun from above the polar regions enables further scientific advantages, beyond those related to the solar cycle, such as unique and powerful studies of coronal mass ejection processes, from a global perspective, and studies of coronal structure and activity in polar regions. Not only will these provide important scientific advances for fundamental stellar physics research, they will feed into our understanding of impacts on the Earth and other planets' space environment. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.10876v1-abstract-full').style.display = 'none'; document.getElementById('2104.10876v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">29 pages, 9 figures, White paper for ESA Voyage 2050</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.07037">arXiv:2101.07037</a> <span> [<a href="https://arxiv.org/pdf/2101.07037">pdf</a>, <a href="https://arxiv.org/format/2101.07037">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> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> </div> </div> <p class="title is-5 mathjax"> SWELTO -- Space WEather Laboratory in Turin Observatory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Abbo%2C+L">L. Abbo</a>, <a href="/search/astro-ph?searchtype=author&query=Barghini%2C+D">D. Barghini</a>, <a href="/search/astro-ph?searchtype=author&query=Benna%2C+C">C. Benna</a>, <a href="/search/astro-ph?searchtype=author&query=Biondo%2C+R">R. Biondo</a>, <a href="/search/astro-ph?searchtype=author&query=Bonino%2C+D">D. Bonino</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">G. Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Carella%2C+F">F. Carella</a>, <a href="/search/astro-ph?searchtype=author&query=Cora%2C+A">A. Cora</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">F. Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Gardiol%2C+D">D. Gardiol</a>, <a href="/search/astro-ph?searchtype=author&query=Giordano%2C+S">S. Giordano</a>, <a href="/search/astro-ph?searchtype=author&query=Liberatore%2C+A">A. Liberatore</a>, <a href="/search/astro-ph?searchtype=author&query=Mancuso%2C+S">S. Mancuso</a>, <a href="/search/astro-ph?searchtype=author&query=Mignone%2C+A">A. Mignone</a>, <a href="/search/astro-ph?searchtype=author&query=Rasetti%2C+S">S. Rasetti</a>, <a href="/search/astro-ph?searchtype=author&query=Reale%2C+F">F. Reale</a>, <a href="/search/astro-ph?searchtype=author&query=Riva%2C+A">A. Riva</a>, <a href="/search/astro-ph?searchtype=author&query=Salvati%2C+F">F. Salvati</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Volpicelli%2C+A">A. Volpicelli</a>, <a href="/search/astro-ph?searchtype=author&query=Zangrilli%2C+L">L. Zangrilli</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.07037v1-abstract-short" style="display: inline;"> SWELTO -- Space WEather Laboratory in Turin Observatory is a conceptual framework where new ideas for the analysis of space-based and ground-based data are developed and tested. The input data are (but not limited to) remote sensing observations (EUV images of the solar disk, Visible Light coronagraphic images, radio dynamic spectra, etc...), in situ plasma measurements (interplanetary plasma dens… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.07037v1-abstract-full').style.display = 'inline'; document.getElementById('2101.07037v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.07037v1-abstract-full" style="display: none;"> SWELTO -- Space WEather Laboratory in Turin Observatory is a conceptual framework where new ideas for the analysis of space-based and ground-based data are developed and tested. The input data are (but not limited to) remote sensing observations (EUV images of the solar disk, Visible Light coronagraphic images, radio dynamic spectra, etc...), in situ plasma measurements (interplanetary plasma density, velocity, magnetic field, etc...), as well as measurements acquired by local sensors and detectors (radio antenna, fluxgate magnetometer, full-sky cameras, located in OATo). The output products are automatic identification, tracking, and monitoring of solar stationary and dynamic features near the Sun (coronal holes, active regions, coronal mass ejections, etc...), and in the interplanetary medium (shocks, plasmoids, corotating interaction regions, etc...), as well as reconstructions of the interplanetary medium where solar disturbances may propagate from the Sun to the Earth and beyond. These are based both on empirical models and numerical MHD simulations. The aim of SWELTO is not only to test new data analysis methods for future application for Space Weather monitoring and prediction purposes, but also to procure, test and deploy new ground-based instrumentation to monitor the ionospheric and geomagnetic responses to solar activity. Moreover, people involved in SWELTO are active in outreach to disseminate the topics related with Space Weather to students and the general public. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.07037v1-abstract-full').style.display = 'none'; document.getElementById('2101.07037v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Published in the INAF Technical Reports series, num. 40, 2020 (https://openaccess.inaf.it/handle/20.500.12386/27715) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2009.10772">arXiv:2009.10772</a> <span> [<a href="https://arxiv.org/pdf/2009.10772">pdf</a>, <a href="https://arxiv.org/format/2009.10772">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/10.1051/0004-6361/202038445">10.1051/0004-6361/202038445 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Solar Orbiter Science Activity Plan: translating solar and heliospheric physics questions into action </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Zouganelis%2C+I">I. Zouganelis</a>, <a href="/search/astro-ph?searchtype=author&query=De+Groof%2C+A">A. De Groof</a>, <a href="/search/astro-ph?searchtype=author&query=Walsh%2C+A+P">A. P. Walsh</a>, <a href="/search/astro-ph?searchtype=author&query=Williams%2C+D+R">D. R. Williams</a>, <a href="/search/astro-ph?searchtype=author&query=Mueller%2C+D">D. Mueller</a>, <a href="/search/astro-ph?searchtype=author&query=Cyr%2C+O+C+S">O. C. St Cyr</a>, <a href="/search/astro-ph?searchtype=author&query=Auchere%2C+F">F. Auchere</a>, <a href="/search/astro-ph?searchtype=author&query=Berghmans%2C+D">D. Berghmans</a>, <a href="/search/astro-ph?searchtype=author&query=Fludra%2C+A">A. Fludra</a>, <a href="/search/astro-ph?searchtype=author&query=Horbury%2C+T+S">T. S. Horbury</a>, <a href="/search/astro-ph?searchtype=author&query=Howard%2C+R+A">R. A. Howard</a>, <a href="/search/astro-ph?searchtype=author&query=Krucker%2C+S">S. Krucker</a>, <a href="/search/astro-ph?searchtype=author&query=Maksimovic%2C+M">M. Maksimovic</a>, <a href="/search/astro-ph?searchtype=author&query=Owen%2C+C+J">C. J. Owen</a>, <a href="/search/astro-ph?searchtype=author&query=Rodriiguez-Pacheco%2C+J">J. Rodriiguez-Pacheco</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Solanki%2C+S+K">S. K. Solanki</a>, <a href="/search/astro-ph?searchtype=author&query=Watson%2C+C">C. Watson</a>, <a href="/search/astro-ph?searchtype=author&query=Sanchez%2C+L">L. Sanchez</a>, <a href="/search/astro-ph?searchtype=author&query=Lefort%2C+J">J. Lefort</a>, <a href="/search/astro-ph?searchtype=author&query=Osuna%2C+P">P. Osuna</a>, <a href="/search/astro-ph?searchtype=author&query=Gilbert%2C+H+R">H. R. Gilbert</a>, <a href="/search/astro-ph?searchtype=author&query=Nieves-Chinchilla%2C+T">T. Nieves-Chinchilla</a>, <a href="/search/astro-ph?searchtype=author&query=Abbo%2C+L">L. Abbo</a>, <a href="/search/astro-ph?searchtype=author&query=Alexandrova%2C+O">O. Alexandrova</a> , et al. (160 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="2009.10772v1-abstract-short" style="display: inline;"> Solar Orbiter is the first space mission observing the solar plasma both in situ and remotely, from a close distance, in and out of the ecliptic. The ultimate goal is to understand how the Sun produces and controls the heliosphere, filling the Solar System and driving the planetary environments. With six remote-sensing and four in-situ instrument suites, the coordination and planning of the operat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.10772v1-abstract-full').style.display = 'inline'; document.getElementById('2009.10772v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.10772v1-abstract-full" style="display: none;"> Solar Orbiter is the first space mission observing the solar plasma both in situ and remotely, from a close distance, in and out of the ecliptic. The ultimate goal is to understand how the Sun produces and controls the heliosphere, filling the Solar System and driving the planetary environments. With six remote-sensing and four in-situ instrument suites, the coordination and planning of the operations are essential to address the following four top-level science questions: (1) What drives the solar wind and where does the coronal magnetic field originate? (2) How do solar transients drive heliospheric variability? (3) How do solar eruptions produce energetic particle radiation that fills the heliosphere? (4) How does the solar dynamo work and drive connections between the Sun and the heliosphere? Maximising the mission's science return requires considering the characteristics of each orbit, including the relative position of the spacecraft to Earth (affecting downlink rates), trajectory events (such as gravitational assist manoeuvres), and the phase of the solar activity cycle. Furthermore, since each orbit's science telemetry will be downloaded over the course of the following orbit, science operations must be planned at mission level, rather than at the level of individual orbits. It is important to explore the way in which those science questions are translated into an actual plan of observations that fits into the mission, thus ensuring that no opportunities are missed. First, the overarching goals are broken down into specific, answerable questions along with the required observations and the so-called Science Activity Plan (SAP) is developed to achieve this. The SAP groups objectives that require similar observations into Solar Orbiter Observing Plans (SOOPs), resulting in a strategic, top-level view of the optimal opportunities for science observations during the mission lifetime. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.10772v1-abstract-full').style.display = 'none'; document.getElementById('2009.10772v1-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 September, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages, 1 figure, accepted by Astronomy & Astrophysics</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 642, A3 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2007.08940">arXiv:2007.08940</a> <span> [<a href="https://arxiv.org/pdf/2007.08940">pdf</a>, <a href="https://arxiv.org/format/2007.08940">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/1538-4357/aba437">10.3847/1538-4357/aba437 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the Possibilities of Detecting Helium D$_3$ Line Polarization with Metis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">Petr Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=%C5%A0t%C4%9Bp%C3%A1n%2C+J">Ji艡铆艩t臎p谩n</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">Alessandro Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Jej%C4%8Di%C4%8D%2C+S">Sonja Jej膷i膷</a>, <a href="/search/astro-ph?searchtype=author&query=Labrosse%2C+N">Nicolas Labrosse</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</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="2007.08940v1-abstract-short" style="display: inline;"> Space coronagraph Metis on board of the Solar Orbiter offers us new capabilities for studying eruptive prominences and coronal mass ejections (CME). Its two spectral channels, hydrogen L$伪$ and visible-light (VL) will provide, for the first time, co-aligned and co-temporal images to study dynamics and plasma properties of CMEs. Moreover, with the VL channel (580 - 640 nm) we find an exciting possi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.08940v1-abstract-full').style.display = 'inline'; document.getElementById('2007.08940v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.08940v1-abstract-full" style="display: none;"> Space coronagraph Metis on board of the Solar Orbiter offers us new capabilities for studying eruptive prominences and coronal mass ejections (CME). Its two spectral channels, hydrogen L$伪$ and visible-light (VL) will provide, for the first time, co-aligned and co-temporal images to study dynamics and plasma properties of CMEs. Moreover, with the VL channel (580 - 640 nm) we find an exciting possibility to detect the helium D$_3$ line (587.73 nm) and its linear polarization. The aim of this study is to predict the diagnostics potential of this line regarding the CME thermal and magnetic structure. For a grid of models we first compute the intensity of the D$_3$ line together with VL continuum intensity due to Thomson scattering on core electrons. We show that the Metis VL channel will detect a mixture of both, with predominance of the helium emission at intermediate temperatures between 30 - 50,000 K. Then we use the code HAZEL to compute the degree of linear polarization detectable in the VL channel. This is a mixture of D$_3$ scattering polarization and continuum polarization. The former one is lowered in the presence of a magnetic field and the polarization axis is rotated (Hanle effect). Metis has the capability of measuring $Q/I$ and $U/I$ polarization degrees and we show their dependence on temperature and magnetic field. At $T$=30,000 K we find a significant lowering of $Q/I$ which is due to strongly enhanced D$_3$ line emission, while depolarization at 10 G amounts roughly to 10 \%. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.08940v1-abstract-full').style.display = 'none'; document.getElementById('2007.08940v1-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 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 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">11 pages, 6 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/1911.08462">arXiv:1911.08462</a> <span> [<a href="https://arxiv.org/pdf/1911.08462">pdf</a>, <a href="https://arxiv.org/format/1911.08462">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/10.1051/0004-6361/201935338">10.1051/0004-6361/201935338 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Metis: the Solar Orbiter visible light and ultraviolet coronal imager </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">Ester Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">Marco Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">Petr Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=Moses%2C+J+D">J. Daniel Moses</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">Giampiero Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">Gianalfredo Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">Daniele Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Teriaca%2C+L">Luca Teriaca</a>, <a href="/search/astro-ph?searchtype=author&query=Berlicki%2C+A">Arkadiusz Berlicki</a>, <a href="/search/astro-ph?searchtype=author&query=Capobianco%2C+G">Gerardo Capobianco</a>, <a href="/search/astro-ph?searchtype=author&query=Crescenzio%2C+G">Giuseppe Crescenzio</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">Vania Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Focardi%2C+M">Mauro Focardi</a>, <a href="/search/astro-ph?searchtype=author&query=Frassetto%2C+F">Fabio Frassetto</a>, <a href="/search/astro-ph?searchtype=author&query=Heerlein%2C+K">Klaus Heerlein</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">Federico Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Magli%2C+E">Enrico Magli</a>, <a href="/search/astro-ph?searchtype=author&query=Malvezzi%2C+A+M">Andrea Marco Malvezzi</a>, <a href="/search/astro-ph?searchtype=author&query=Massone%2C+G">Giuseppe Massone</a>, <a href="/search/astro-ph?searchtype=author&query=Melich%2C+R">Radek Melich</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolosi%2C+P">Piergiorgio Nicolosi</a>, <a href="/search/astro-ph?searchtype=author&query=Noci%2C+G">Giancarlo Noci</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">Maurizio Pancrazzi</a> , et al. (78 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="1911.08462v1-abstract-short" style="display: inline;"> Metis is the first solar coronagraph designed for a space mission capable of performing simultaneous imaging of the off-limb solar corona in both visible and UV light. The observations obtained with Metis aboard the Solar Orbiter ESA-NASA observatory will enable us to diagnose, with unprecedented temporal coverage and spatial resolution, the structures and dynamics of the full corona from 1.7… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.08462v1-abstract-full').style.display = 'inline'; document.getElementById('1911.08462v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1911.08462v1-abstract-full" style="display: none;"> Metis is the first solar coronagraph designed for a space mission capable of performing simultaneous imaging of the off-limb solar corona in both visible and UV light. The observations obtained with Metis aboard the Solar Orbiter ESA-NASA observatory will enable us to diagnose, with unprecedented temporal coverage and spatial resolution, the structures and dynamics of the full corona from 1.7 $R_\odot$ to about 9 $R_\odot$. Due to the uniqueness of the Solar Orbiter mission profile, Metis will be able to observe the solar corona from a close vantage point (down to 0.28 AU), achieving out-of-ecliptic views with the increase of the orbit inclination over time. Moreover, observations near perihelion, during the phase of lower rotational velocity of the solar surface relative to the spacecraft, will allow longer-term studies of the coronal features. Thanks to a novel occultation design and a combination of a UV interference coating of the mirrors and a spectral bandpass filter, Metis images the solar corona simultaneously in the visible light band, between 580 and 640 nm, and in the UV H I Lyman-伪 line at 121.6 nm. The coronal images in both the UV Lyman-伪 and polarised visible light are obtained at high spatial resolution with a spatial scale down to about 2000 km and 15000 km at perihelion, in the cases of the visible and UV light, respectively. A temporal resolution down to 1 second can be achieved when observing coronal fluctuations in visible light. The Metis measurements will allow for complete characterisation of the main physical parameters and dynamics of the electron and neutral hydrogen/proton plasma components of the corona in the region where the solar wind undergoes acceleration and where the onset and initial propagation of coronal mass ejections take place, thus significantly improving our understanding of the region connecting the Sun to the heliosphere. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.08462v1-abstract-full').style.display = 'none'; document.getElementById('1911.08462v1-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 November, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1905.09005">arXiv:1905.09005</a> <span> [<a href="https://arxiv.org/pdf/1905.09005">pdf</a>, <a href="https://arxiv.org/format/1905.09005">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="Space Physics">physics.space-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/10.1051/0004-6361/201834125">10.1051/0004-6361/201834125 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Comparing extrapolations of the coronal magnetic field structure at 2.5 solar radii with multi-viewpoint coronagraphic observations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Sasso%2C+C">C. Sasso</a>, <a href="/search/astro-ph?searchtype=author&query=Pinto%2C+R+F">R. F. Pinto</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Howard%2C+R+A">R. A. Howard</a>, <a href="/search/astro-ph?searchtype=author&query=Vourlidas%2C+A">A. Vourlidas</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Dolei%2C+S">S. Dolei</a>, <a href="/search/astro-ph?searchtype=author&query=Spadaro%2C+D">D. Spadaro</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">R. Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Antonucci%2C+E">E. Antonucci</a>, <a href="/search/astro-ph?searchtype=author&query=Abbo%2C+L">L. Abbo</a>, <a href="/search/astro-ph?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Frassetto%2C+F">F. Frassetto</a>, <a href="/search/astro-ph?searchtype=author&query=Landini%2C+F">F. Landini</a>, <a href="/search/astro-ph?searchtype=author&query=Naletto%2C+G">G. Naletto</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolini%2C+G">G. Nicolini</a>, <a href="/search/astro-ph?searchtype=author&query=Nicolosi%2C+P">P. Nicolosi</a>, <a href="/search/astro-ph?searchtype=author&query=Pancrazzi%2C+M">M. Pancrazzi</a>, <a href="/search/astro-ph?searchtype=author&query=Romoli%2C+M">M. Romoli</a>, <a href="/search/astro-ph?searchtype=author&query=Telloni%2C+D">D. Telloni</a>, <a href="/search/astro-ph?searchtype=author&query=Ventura%2C+R">R. Ventura</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="1905.09005v1-abstract-short" style="display: inline;"> The magnetic field shapes the structure of the solar corona but we still know little about the interrelationships between the coronal magnetic field configurations and the resulting quasi-stationary structures observed in coronagraphic images (as streamers, plumes, coronal holes). One way to obtain information on the large-scale structure of the coronal magnetic field is to extrapolate it from pho… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.09005v1-abstract-full').style.display = 'inline'; document.getElementById('1905.09005v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1905.09005v1-abstract-full" style="display: none;"> The magnetic field shapes the structure of the solar corona but we still know little about the interrelationships between the coronal magnetic field configurations and the resulting quasi-stationary structures observed in coronagraphic images (as streamers, plumes, coronal holes). One way to obtain information on the large-scale structure of the coronal magnetic field is to extrapolate it from photospheric data and compare the results with coronagraphic images. Our aim is to verify if this comparison can be a fast method to check systematically the reliability of the many methods available to reconstruct the coronal magnetic field. Coronal fields are usually extrapolated from photospheric measurements typically in a region close to the central meridian on the solar disk and then compared with coronagraphic images at the limbs, acquired at least 7 days before or after to account for solar rotation, implicitly assuming that no significant changes occurred in the corona during that period. In this work, we combine images from three coronagraphs (SOHO/LASCO-C2 and the two STEREO/SECCHI-COR1) observing the Sun from different viewing angles to build Carrington maps covering the entire corona to reduce the effect of temporal evolution to ~ 5 days. We then compare the position of the observed streamers in these Carrington maps with that of the neutral lines obtained from four different magnetic field extrapolations, to evaluate the performances of the latter in the solar corona. Our results show that the location of coronal streamers can provide important indications to discriminate between different magnetic field extrapolations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.09005v1-abstract-full').style.display = 'none'; document.getElementById('1905.09005v1-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 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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 by A&A the 20th of May, 2019</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> A&A 627, A9 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1807.00155">arXiv:1807.00155</a> <span> [<a href="https://arxiv.org/pdf/1807.00155">pdf</a>, <a href="https://arxiv.org/ps/1807.00155">ps</a>, <a href="https://arxiv.org/format/1807.00155">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/10.1007/s11207-018-1251-3">10.1007/s11207-018-1251-3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Visibility of Prominences using the HeI D3 Line Filter on PROBA-3/ASPIICS Coronagraph </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Jej%C4%8Di%C4%8D%2C+S">S. Jej膷i膷</a>, <a href="/search/astro-ph?searchtype=author&query=Heinzel%2C+P">P. Heinzel</a>, <a href="/search/astro-ph?searchtype=author&query=Labrosse%2C+N">N. Labrosse</a>, <a href="/search/astro-ph?searchtype=author&query=Zhukov%2C+A+N">A. N. Zhukov</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Gun%C3%A1r%2C+S">S. Gun谩r</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="1807.00155v1-abstract-short" style="display: inline;"> We determine an optimal width and shape of the narrow-band filter centered around the He\,{\sc i} D$_{3}$ line for prominence and coronal mass ejection (CME) observations with the ASPIICS ({\it Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun}) coronagraph onboard the PROBA-3 ({\it Project for On-board Autonomy}) satellite, to be launched in 2020. We an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1807.00155v1-abstract-full').style.display = 'inline'; document.getElementById('1807.00155v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1807.00155v1-abstract-full" style="display: none;"> We determine an optimal width and shape of the narrow-band filter centered around the He\,{\sc i} D$_{3}$ line for prominence and coronal mass ejection (CME) observations with the ASPIICS ({\it Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun}) coronagraph onboard the PROBA-3 ({\it Project for On-board Autonomy}) satellite, to be launched in 2020. We analyze He\,{\sc i} D$_{3}$ line intensities for three representative non-LTE prominence models at temperatures 8, 30 and 100~kK computed by the radiative transfer code and the prominence visible-light (VL) emission due to Thomson scattering on the prominence electrons. We compute various useful relations at prominence line-of-sight (LOS) velocities of 0, 100, and 300~km~s$^{-1}$ for 20~脜~wide flat filter and three Gaussian filters with full width at half maximum (FWHM) equal to 5, 10, and 20~脜~to show the relative brightness contribution of the He\,{\sc i} D$_{3}$ line and the prominence VL to the visibility in a given narrow-band filter. We also discuss possible signal contamination by Na\,{\sc i} D$_{1}$ and D$_{2}$ lines which otherwise may be useful to detect comets. Results mainly show: i) an optimal narrow-band filter should be flat or somewhere between flat and Gaussian with FWHM of 20~脜~in order to detect fast moving prominence structures, ii) the maximum emission in the He\,{\sc i} D$_3$ line is at 30~kK and the minimal at 100~kK, and iii) the ratio of emission in the He\,{\sc i} D$_3$ line to the VL emission can provide a useful diagnostic for the temperature of prominence structures. This ratio is up to 10 for hot prominence structures, up to 100 for cool structures and up to 1000 for warm structures. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1807.00155v1-abstract-full').style.display = 'none'; document.getElementById('1807.00155v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 June, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2018. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1608.05536">arXiv:1608.05536</a> <span> [<a href="https://arxiv.org/pdf/1608.05536">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3389/fspas.2016.00017">10.3389/fspas.2016.00017 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measuring coronal magnetic fields with remote sensing observations of shock waves </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">Alessandro Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Susino%2C+R">Roberto Susino</a>, <a href="/search/astro-ph?searchtype=author&query=Frassati%2C+F">Federica Frassati</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</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="1608.05536v1-abstract-short" style="display: inline;"> Recent works demonstrated that remote sensing observations of shock waves propagating into the corona and associated with major solar eruptions can be used to derive the strength of coronal magnetic fields met by the shock over a very large interval of heliocentric distances and latitudes. This opinion article will summarize most recent results obtained on this topic and will discuss the weaknesse… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.05536v1-abstract-full').style.display = 'inline'; document.getElementById('1608.05536v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1608.05536v1-abstract-full" style="display: none;"> Recent works demonstrated that remote sensing observations of shock waves propagating into the corona and associated with major solar eruptions can be used to derive the strength of coronal magnetic fields met by the shock over a very large interval of heliocentric distances and latitudes. This opinion article will summarize most recent results obtained on this topic and will discuss the weaknesses and strengths of these techniques to open a constructive discussion with the scientific community. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.05536v1-abstract-full').style.display = 'none'; document.getElementById('1608.05536v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 August, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 1 figure</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Frontiers in Astronomy and Space Sciences, Volume 3, id.17 (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1606.08493">arXiv:1606.08493</a> <span> [<a href="https://arxiv.org/pdf/1606.08493">pdf</a>, <a href="https://arxiv.org/format/1606.08493">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/10.3389/fspas.2016.00020">10.3389/fspas.2016.00020 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Diagnostics of Coronal Magnetic Fields Through the Hanle Effect in UV and IR Lines </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Raouafi%2C+N+E">N. E. Raouafi</a>, <a href="/search/astro-ph?searchtype=author&query=Riley%2C+P">P. Riley</a>, <a href="/search/astro-ph?searchtype=author&query=Gibson%2C+S">S. Gibson</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Solanki%2C+S+K">S. K. Solanki</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="1606.08493v1-abstract-short" style="display: inline;"> The plasma thermodynamics in the solar upper atmosphere, particularly in the corona, are dominated by the magnetic field, which controls the flow and dissipation of energy. The relative lack of knowledge of the coronal vector magnetic field is a major handicap for progress in coronal physics. This makes the development of measurement methods of coronal magnetic fields a high priority in solar phys… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.08493v1-abstract-full').style.display = 'inline'; document.getElementById('1606.08493v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1606.08493v1-abstract-full" style="display: none;"> The plasma thermodynamics in the solar upper atmosphere, particularly in the corona, are dominated by the magnetic field, which controls the flow and dissipation of energy. The relative lack of knowledge of the coronal vector magnetic field is a major handicap for progress in coronal physics. This makes the development of measurement methods of coronal magnetic fields a high priority in solar physics. The Hanle effect in the UV and IR spectral lines is a largely unexplored diagnostic. We use magnetohydrodynamic (MHD) simulations to study the magnitude of the signal to be expected for typical coronal magnetic fields for selected spectral lines in the UV and IR wavelength ranges, namely the H I Ly-$伪$ and the He I 10830 脜 lines. We show that the selected lines are useful for reliable diagnosis of coronal magnetic fields. The results show that the combination of polarization measurements of spectral lines with different sensitivities to the Hanle effect may be most appropriate for deducing coronal magnetic properties from future observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.08493v1-abstract-full').style.display = 'none'; document.getElementById('1606.08493v1-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 June, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 5 figures, Frontiers in Astronomy and Space Sciences, 2016</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1109.4301">arXiv:1109.4301</a> <span> [<a href="https://arxiv.org/pdf/1109.4301">pdf</a>, <a href="https://arxiv.org/ps/1109.4301">ps</a>, <a href="https://arxiv.org/format/1109.4301">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/10.1007/s10686-011-9274-x">10.1007/s10686-011-9274-x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> LEMUR: Large European Module for solar Ultraviolet Research. European contribution to JAXA's Solar-C mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Teriaca%2C+L">Luca Teriaca</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">Vincenzo Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Auch%C3%A8re%2C+F">Fr茅d茅ric Auch猫re</a>, <a href="/search/astro-ph?searchtype=author&query=Brown%2C+C+M">Charles M. Brown</a>, <a href="/search/astro-ph?searchtype=author&query=Buchlin%2C+E">Eric Buchlin</a>, <a href="/search/astro-ph?searchtype=author&query=Cauzzi%2C+G">Gianna Cauzzi</a>, <a href="/search/astro-ph?searchtype=author&query=Culhane%2C+J+L">J. Len Culhane</a>, <a href="/search/astro-ph?searchtype=author&query=Curdt%2C+W">Werner Curdt</a>, <a href="/search/astro-ph?searchtype=author&query=Davila%2C+J+M">Joseph M. Davila</a>, <a href="/search/astro-ph?searchtype=author&query=Del+Zanna%2C+G">Giulio Del Zanna</a>, <a href="/search/astro-ph?searchtype=author&query=Doschek%2C+G+A">George A. Doschek</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">Silvano Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Fludra%2C+A">Andrzej Fludra</a>, <a href="/search/astro-ph?searchtype=author&query=Gallagher%2C+P+T">Peter T. Gallagher</a>, <a href="/search/astro-ph?searchtype=author&query=Green%2C+L">Lucie Green</a>, <a href="/search/astro-ph?searchtype=author&query=Harra%2C+L+K">Louise K. Harra</a>, <a href="/search/astro-ph?searchtype=author&query=Imada%2C+S">Shinsuke Imada</a>, <a href="/search/astro-ph?searchtype=author&query=Innes%2C+D">Davina Innes</a>, <a href="/search/astro-ph?searchtype=author&query=Kliem%2C+B">Bernhard Kliem</a>, <a href="/search/astro-ph?searchtype=author&query=Korendyke%2C+C">Clarence Korendyke</a>, <a href="/search/astro-ph?searchtype=author&query=Mariska%2C+J+T">John T. Mariska</a>, <a href="/search/astro-ph?searchtype=author&query=Mart%C3%ADnez-Pillet%2C+V">Valentin Mart铆nez-Pillet</a>, <a href="/search/astro-ph?searchtype=author&query=Parenti%2C+S">Susanna Parenti</a>, <a href="/search/astro-ph?searchtype=author&query=Patsourakos%2C+S">Spiros Patsourakos</a>, <a href="/search/astro-ph?searchtype=author&query=Peter%2C+H">Hardi Peter</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="1109.4301v2-abstract-short" style="display: inline;"> Understanding the solar outer atmosphere requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1" and 0.3"), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1109.4301v2-abstract-full').style.display = 'inline'; document.getElementById('1109.4301v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1109.4301v2-abstract-full" style="display: none;"> Understanding the solar outer atmosphere requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1" and 0.3"), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 17 and 127 nm. The LEMUR slit covers 280" on the Sun with 0.14" per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km/s or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1109.4301v2-abstract-full').style.display = 'none'; document.getElementById('1109.4301v2-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 September, 2011; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 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">35 pages, 14 figures. To appear on Experimental Astronomy</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1108.5304">arXiv:1108.5304</a> <span> [<a href="https://arxiv.org/pdf/1108.5304">pdf</a>, <a href="https://arxiv.org/format/1108.5304">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="Plasma Physics">physics.plasm-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-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/10.1007/s10686-011-9271-0">10.1007/s10686-011-9271-0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Solar magnetism eXplorer (SolmeX) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Peter%2C+H">H. Peter</a>, <a href="/search/astro-ph?searchtype=author&query=Abbo%2C+L">L. Abbo</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Auchere%2C+F">F. Auchere</a>, <a href="/search/astro-ph?searchtype=author&query=Bemporad%2C+A">A. Bemporad</a>, <a href="/search/astro-ph?searchtype=author&query=Berrilli%2C+F">F. Berrilli</a>, <a href="/search/astro-ph?searchtype=author&query=Bommier%2C+V">V. Bommier</a>, <a href="/search/astro-ph?searchtype=author&query=Braukhane%2C+A">A. Braukhane</a>, <a href="/search/astro-ph?searchtype=author&query=Casini%2C+R">R. Casini</a>, <a href="/search/astro-ph?searchtype=author&query=Curdt%2C+W">W. Curdt</a>, <a href="/search/astro-ph?searchtype=author&query=Davila%2C+J">J. Davila</a>, <a href="/search/astro-ph?searchtype=author&query=Dittus%2C+H">H. Dittus</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Fludra%2C+A">A. Fludra</a>, <a href="/search/astro-ph?searchtype=author&query=Gandorfer%2C+A">A. Gandorfer</a>, <a href="/search/astro-ph?searchtype=author&query=Griffin%2C+D">D. Griffin</a>, <a href="/search/astro-ph?searchtype=author&query=Inhester%2C+B">B. Inhester</a>, <a href="/search/astro-ph?searchtype=author&query=Lagg%2C+A">A. Lagg</a>, <a href="/search/astro-ph?searchtype=author&query=Degl%27Innocenti%2C+E+L">E. Landi Degl'Innocenti</a>, <a href="/search/astro-ph?searchtype=author&query=Maiwald%2C+V">V. Maiwald</a>, <a href="/search/astro-ph?searchtype=author&query=Sainz%2C+R+M">R. Manso Sainz</a>, <a href="/search/astro-ph?searchtype=author&query=Pillet%2C+V+M">V. Martinez Pillet</a>, <a href="/search/astro-ph?searchtype=author&query=Matthews%2C+S">S. Matthews</a>, <a href="/search/astro-ph?searchtype=author&query=Moses%2C+D">D. Moses</a>, <a href="/search/astro-ph?searchtype=author&query=Parenti%2C+S">S. Parenti</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="1108.5304v1-abstract-short" style="display: inline;"> The magnetic field plays a pivotal role in many fields of Astrophysics. This is especially true for the physics of the solar atmosphere. Measuring the magnetic field in the upper solar atmosphere is crucial to understand the nature of the underlying physical processes that drive the violent dynamics of the solar corona -- that can also affect life on Earth. SolmeX, a fully equipped solar space o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1108.5304v1-abstract-full').style.display = 'inline'; document.getElementById('1108.5304v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1108.5304v1-abstract-full" style="display: none;"> The magnetic field plays a pivotal role in many fields of Astrophysics. This is especially true for the physics of the solar atmosphere. Measuring the magnetic field in the upper solar atmosphere is crucial to understand the nature of the underlying physical processes that drive the violent dynamics of the solar corona -- that can also affect life on Earth. SolmeX, a fully equipped solar space observatory for remote-sensing observations, will provide the first comprehensive measurements of the strength and direction of the magnetic field in the upper solar atmosphere. The mission consists of two spacecraft, one carrying the instruments, and another one in formation flight at a distance of about 200m carrying the occulter to provide an artificial total solar eclipse. This will ensure high-quality coronagraphic observations above the solar limb. Solmex integrates two spectro-polarimetric coronagraphs for off-limb observations, one in the EUV and one in the IR, and three instruments for observations on the disk. The latter comprises one imaging polarimeter in the EUV for coronal studies, a spectro-polarimeter in the EUV to investigate the low corona, and an imaging spectro-polarimeter in the UV for chromospheric studies. SOHO and other existing missions have investigated the emission of the upper atmosphere in detail (not considering polarization), and as this will be the case also for missions planned for the near future. Therefore it is timely that SolmeX provides the final piece of the observational quest by measuring the magnetic field in the upper atmosphere through polarimetric observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1108.5304v1-abstract-full').style.display = 'none'; document.getElementById('1108.5304v1-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, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">Submitted to Experimental Astronomy. 30 pages, 19 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/0805.4389">arXiv:0805.4389</a> <span> [<a href="https://arxiv.org/pdf/0805.4389">pdf</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/10.1007/s10686-008-9107-8">10.1007/s10686-008-9107-8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> POLAR Investigation of the Sun - POLARIS </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Appourchaux%2C+T">T. Appourchaux</a>, <a href="/search/astro-ph?searchtype=author&query=Liewer%2C+P">P. Liewer</a>, <a href="/search/astro-ph?searchtype=author&query=Watt%2C+M">M. Watt</a>, <a href="/search/astro-ph?searchtype=author&query=Alexander%2C+D">D. Alexander</a>, <a href="/search/astro-ph?searchtype=author&query=Andretta%2C+V">V. Andretta</a>, <a href="/search/astro-ph?searchtype=author&query=Auchere%2C+F">F. Auchere</a>, <a href="/search/astro-ph?searchtype=author&query=D%27Arrigo%2C+P">P. D'Arrigo</a>, <a href="/search/astro-ph?searchtype=author&query=Ayon%2C+J">J. Ayon</a>, <a href="/search/astro-ph?searchtype=author&query=Corbard%2C+T">T. Corbard</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=Finsterle%2C+W">W. Finsterle</a>, <a href="/search/astro-ph?searchtype=author&query=Floyd%2C+L">L. Floyd</a>, <a href="/search/astro-ph?searchtype=author&query=Garbe%2C+G">G. Garbe</a>, <a href="/search/astro-ph?searchtype=author&query=Gizon%2C+L">L. Gizon</a>, <a href="/search/astro-ph?searchtype=author&query=Hassler%2C+D">D. Hassler</a>, <a href="/search/astro-ph?searchtype=author&query=Harra%2C+L">L. Harra</a>, <a href="/search/astro-ph?searchtype=author&query=Kosovichev%2C+A">A. Kosovichev</a>, <a href="/search/astro-ph?searchtype=author&query=Leibacher%2C+J">J. Leibacher</a>, <a href="/search/astro-ph?searchtype=author&query=Leipold%2C+M">M. Leipold</a>, <a href="/search/astro-ph?searchtype=author&query=Murphy%2C+N">N. Murphy</a>, <a href="/search/astro-ph?searchtype=author&query=Maksimovic%2C+M">M. Maksimovic</a>, <a href="/search/astro-ph?searchtype=author&query=Martinez-Pillet%2C+V">V. Martinez-Pillet</a>, <a href="/search/astro-ph?searchtype=author&query=Matthews%2C+B+S+A">B. S. A. Matthews</a>, <a href="/search/astro-ph?searchtype=author&query=Mewaldt%2C+R">R. Mewaldt</a>, <a href="/search/astro-ph?searchtype=author&query=Moses%2C+D">D. Moses</a> , et al. (12 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="0805.4389v2-abstract-short" style="display: inline;"> The POLAR Investigation of the Sun (POLARIS) mission uses a combination of a gravity assist and solar sail propulsion to place a spacecraft in a 0.48 AU circular orbit around the Sun with an inclination of 75 degrees with respect to solar equator. This challenging orbit is made possible by the challenging development of solar sail propulsion. This first extended view of the high-latitude regions… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0805.4389v2-abstract-full').style.display = 'inline'; document.getElementById('0805.4389v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0805.4389v2-abstract-full" style="display: none;"> The POLAR Investigation of the Sun (POLARIS) mission uses a combination of a gravity assist and solar sail propulsion to place a spacecraft in a 0.48 AU circular orbit around the Sun with an inclination of 75 degrees with respect to solar equator. This challenging orbit is made possible by the challenging development of solar sail propulsion. This first extended view of the high-latitude regions of the Sun will enable crucial observations not possible from the ecliptic viewpoint or from Solar Orbiter. While Solar Orbiter would give the first glimpse of the high latitude magnetic field and flows to probe the solar dynamo, it does not have sufficient viewing of the polar regions to achieve POLARIS' primary objective : determining the relation between the magnetism and dynamics of the Sun's polar regions and the solar cycle. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0805.4389v2-abstract-full').style.display = 'none'; document.getElementById('0805.4389v2-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 June, 2008; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 May, 2008; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">23 pages, 14 figures, 4 tables, Accepted by Experimental Astronomy</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/9709021">arXiv:astro-ph/9709021</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/9709021">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/9709021">ps</a>, <a href="https://arxiv.org/format/astro-ph/9709021">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/10.1086/310970">10.1086/310970 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Origins of the slow and the ubiquitous fast solar wind </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/astro-ph?searchtype=author&query=Habbal%2C+S+R">S. R. Habbal</a>, <a href="/search/astro-ph?searchtype=author&query=Woo%2C+R">R. Woo</a>, <a href="/search/astro-ph?searchtype=author&query=Fineschi%2C+S">S. Fineschi</a>, <a href="/search/astro-ph?searchtype=author&query=O%27Neal%2C+R">R. O'Neal</a>, <a href="/search/astro-ph?searchtype=author&query=Kohl%2C+J">J. Kohl</a>, <a href="/search/astro-ph?searchtype=author&query=Noci%2C+G">G. Noci</a>, <a href="/search/astro-ph?searchtype=author&query=Korendyke%2C+C">C. Korendyke</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/9709021v1-abstract-short" style="display: inline;"> We present in this Letter the first coordinated radio occultation measurements and ultraviolet observations of the inner corona below 5.5 Rs, obtained during the Galileo solar conjunction in January 1997, to establish the origin of the slow solar wind. Limits on the flow speed are derived from the Doppler dimming of the resonantly scattered componentof the oxygen 1032 A and 1037 A lines as measu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/9709021v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/9709021v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/9709021v1-abstract-full" style="display: none;"> We present in this Letter the first coordinated radio occultation measurements and ultraviolet observations of the inner corona below 5.5 Rs, obtained during the Galileo solar conjunction in January 1997, to establish the origin of the slow solar wind. Limits on the flow speed are derived from the Doppler dimming of the resonantly scattered componentof the oxygen 1032 A and 1037 A lines as measured with the UltraViolet Coronagraph Spectrometer (UVCS) on the Solar and Heliospheric Observatory (SOHO). White light images of the corona from the Large Angle Spectroscopic Coronagraph (LASCO) on SOHO taken simultaneously are used to place the Doppler radio scintillation and ultraviolet measurements in the context ofcoronal structures. These combined observations provide the first direct confirmation of the view recently proposed by Woo and Martin (1997) that the slow solar wind is associated with the axes, also known as stalks, of streamers. Furthermore, the ultraviolet observations also show how the fast solar wind is ubiquitous in the inner corona, and that a velocity shear between the fast and slow solar wind develops along the streamer stalks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/9709021v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/9709021v1-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, 1997; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 1997. </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, LaTex, 6 jpg figures, accepted Aug. 28, 1997 for publication in the ApJ Letters</span> </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" 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