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9 results on '"Thierry Morel"'

1. Gaia Early Data Release 3 The Gaia Catalogue of Nearby Stars

Author

Zoltan Balog, G. Tauran, Vincenzo Ripepi, Gerry Gilmore, M. Barros, Łukasz Wyrzykowski, Alberto Cellino, E. Poggio, P. Gavras, Simchon Faigler, Marc Audard, C. Nicolas, M. Vaillant, A. Mora, Paolo Tanga, Silvio Leccia, Despina Hatzidimitriou, A. Dapergolas, Eva Sciacca, Alberto Krone-Martins, N. Cheek, M. Hauser, Ulrike Heiter, S. Managau, L. Rohrbasser, Mathias Schultheis, E. Utrilla, Minia Manteiga, Marcella Marconi, Xavier Luri, F. De Angeli, Shay Zucker, Paolo Giacobbe, J. Juaristi Campillo, H. I. Siddiqui, J. Torra, F. X. Pineau, Roy Gomel, Thierry Morel, T. Cornez, Eric Gosset, Mario Gai, Jose M Hernandez, G. Giuffrida, A. de Torres, Laszlo Szabados, S. Ragaini, E. van Dillen, D. Semeux, Leanne P. Guy, R. Drimmel, L. M. Sarro, S. Voutsinas, Johannes Sahlmann, Damien Ségransan, S. Liao, Derek W. Morris, Jan Rybizki, André Moitinho, T. Roegiers, Bengt Edvardsson, Tristan Cantat-Gaudin, Martin Altmann, C. Turon, Laurent Chemin, K. Janßen, D. Garabato, Alejandra Recio-Blanco, Michał Pawlak, Lorenzo Rimoldini, Sergei A. Klioner, F. Torra, Carine Babusiaux, Alfred Castro-Ginard, G. Plum, Mariateresa Crosta, Iain A. Steele, A. Yoldas, Alex Lobel, J.-L. Bassilana, Harry Enke, Rosanna Sordo, Francesca Fragkoudi, F. De Luise, M. Bernet, Alessandro Sozzetti, M. Kontizas, Roberto Molinaro, C. Diener, S. Regibo, D. Barbato, T. Pauwels, R. E. de Souza, C. Fabricius, D. Souami, L. Martin Polo, M. Ramos-Lerate, Douglas J. Marshall, A. G. Butkevich, P. Madrero Pardo, P. Re Fiorentin, J. F. Le Campion, Jérôme Berthier, N. Tonello, Ummi Abbas, Y. Lebreton, M. Biermann, D. Munoz, N. Brouillet, David Teyssier, O. Vanel, P. A. Palicio, A. Jean-Antoine Piccolo, A. F. Lanza, Jesus Salgado, E. del Pozo, Antti Penttilä, R. Geyer, Ramachrisna Teixeira, L. Chaoul, Mike Smith, Rossella Cancelliere, J. M. Martín-Fleitas, D. Baines, M. Romero-Gómez, E. Anglada Varela, E. Livanou, X. Peñalosa Esteller, S. Diakite, Alberto Vecchiato, Thomas Wevers, Daniel Hestroffer, Sebastian L. Hidalgo, M. David, Angela Bragaglia, J. De Ridder, Mark Taylor, Roberto Morbidelli, A. Sagristà Sellés, Nigel Hambly, Arnaud Siebert, R. L. Smart, P. Burgess, Y. Le Fustec, Alessandro Bressan, H. Steidelmüller, Alberto Riva, H. E. Huckle, Morgan Fouesneau, N. Bauchet, P. Osborne, S. Marinoni, Krzysztof A. Rybicki, A. Masip, Laia Casamiquela, R. Messineo, A. Garofalo, Antonella Vallenari, R. Mor, Sahar Shahaf, P. de Laverny, G. Sadowski, Peter G. Jonker, A. Kochoska, F. Taris, A. F. Mulone, M. Ajaj, C. Ducourant, T. A. Lister, F. A. Jansen, Ruth Carballo, J. M. Carrasco, Tatiana Muraveva, W. van Reeven, P. Sartoretti, Jordi Portell, Andreas Korn, E. Salguero, Ana Ulla, P. Di Matteo, Coryn A. L. Bailer-Jones, J. Bakker, F. Riclet, G. Altavilla, Ulrich Bastian, P. Esquej, R. Buzzi, M. Segol, A. C. Lanzafame, L. Balaguer-Núñez, Beatrice Bucciarelli, C. Panem, E. Balbinot, T. Carlucci, Davide Massari, P. de Teodoro, Sébastien Lambert, M. I. Carnerero, Amina Helmi, F. Solitro, C. Robin, Carlos Dafonte, Tsevi Mazeh, A. Panahi, C. Fabre, Sergi Blanco-Cuaresma, Deborah Busonero, Maroussia Roelens, O. Marchal, Tomaz Zwitter, B. Holl, G. Holland, William Thuillot, Michael Davidson, E. Licata, Michele Bellazzini, Teresa Antoja, E. Szegedi-Elek, Francesca Figueras, Eric Slezak, Sergio Messina, N. Samaras, E. Poujoulet, Mark Cropper, A. Burlacu, R. Blomme, Elmé Breedt, Annie C. Robin, H. E. Delgado, Z. Kostrzewa-Rutkowska, Georges Kordopatis, Conny Aerts, L. Noval, Daniel Michalik, P. J. Richards, L. Karbevska, Grigori Fedorets, Maria Süveges, F. Crifo, J. Guiraud, D. Eappachen, K. Kruszyńska, Gisella Clementini, P. Yvard, Carme Jordi, L. Bramante, G. Busso, P. David, E. Fraile, Ugo Becciani, A. Lorca, Sanjeev Khanna, Alex Bombrun, Isabella Pagano, C. Dolding, A. M. Piersimoni, Paolo Montegriffo, A. Abreu Aramburu, Anthony G. A. Brown, Simon Hodgkin, Ennio Poretti, M. Fabrizio, I. Gonzalez-Santamaria, N. A. Walton, P. Panuzzo, Benoit Carry, Raphael Guerra, J. J. González-Vidal, T. Lebzelter, Nami Mowlavi, C. Barache, M. M. S. Marcos Santos, S. Cowell, Marco Castellani, J. J. Aguado, N. R. Millar, A. Baudesson-Stella, N. Leclerc, S. Bartolomé, J. Álvarez Cid-Fuentes, F. van Leeuwen, S. Bouquillon, Uwe Lammers, D. W. Evans, L. Eyer, M. van Leeuwen, A. Guerrier, J. González-Núñez, H. E. P. Lindstrøm, Miguel García-Torres, Ilaria Musella, L. Palaversa, W. Roux, W. Löffler, J.-B. Delisle, Dimitri Pourbaix, Timo Prusti, J. Osinde, M. Riello, G. Orrù, C. Crowley, Alessandra Mastrobuono-Battisti, Hector Canovas, D. L. Harrison, Y. Lasne, E. F. del Peloso, Laurent Galluccio, N. Hładczuk, T. Boch, Martin A. Barstow, László Molnár, Aldo Dell'Oro, C. Pagani, Krzysztof Nienartowicz, Stefano Bertone, Patrick Charlot, Eduard Masana, Elisabetta Caffau, N. Robichon, Luciana Bianchi, Federica Spoto, Felix Franke, J. L. Halbwachs, R. Gutiérrez-Sánchez, L. Pulone, Yassine Damerdji, Frédéric Arenou, Richard I. Anderson, Elena Pancino, David Hobbs, P. Castro Sampol, Yves Fremat, Pierre Kervella, C. Zurbach, Sofia Randich, Robert G. Mann, J. C. Segovia, Diego Bossini, D. Katz, Nicholas Rowell, P. Ramos, E. Racero, G. Gracia-Abril, R. Santoveña, R. Haigron, N. Unger, Enrique Solano, S. G. Baker, W. J. Cooper, F. Royer, S. Accart, George M. Seabroke, João Alves, Emese Plachy, Thomas Hilger, Pedro García-Lario, Gérard Jasniewicz, Kevin Benson, Christos Siopis, J. Souchay, Agnes Fienga, Giovanni Comoretto, F. Julbe, A. Hutton, Pierre Fernique, Céline Reylé, F. Pailler, Stefan Jordan, J. H. J. de Bruijne, C. A. Stephenson, E. Gerlach, Elisa Distefano, Karri Muinonen, Y. Viala, H. Zhao, L. Siltala, C. P. Murphy, Maria-Rosa L. Cioni, Andrea Chiavassa, D. Molina, J. Fernández-Hernández, G. Jevardat de Fombelle, Federico Marocco, Nicoletta Sanna, Alexey Mints, Juan Zorec, Ángel Gómez, I. Bellas-Velidis, M. G. Lattanzi, C. M. Raiteri, E. Brugaletta, Mikael Granvik, O. L. Creevey, Guy Rixon, Francois Mignard, P. M. Marrese, M. A. Álvarez, Caroline Soubiran, Rene Andrae, C. Ordénovic, A. Delgado, V. Sanchez Gimenez, J. Castañeda, D. Vicente, R. De March, A. Garcia-Gutierrez, M. Weiler, F. Thévenin, Lennart Lindegren, Isabelle Lecoeur-Taïbi, Jon Marchant, Monica Rainer, Alessandro Spagna, Andrej Prsa, M. Sarasso, Nicolas Rambaux, Paul J. McMillan, Ludovic Delchambre, M. Garcia-Reinaldos, M. Haywood, C. Fouron, S. Girona, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Universidad de Barcelona, Xunta de Galicia, Generalitat de Catalunya, INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astronomische Rechen-Institut [Heidelberg] (ARI), Zentrum für Astronomie der Universität Heidelberg (ZAH), Universität Heidelberg [Heidelberg]-Universität Heidelberg [Heidelberg], Systèmes de Référence Temps Espace (SYRTE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Mésocentre de calcul (MESOCENTRE), Université de Franche-Comté (UFC), Centre de Données Astronomiques de Strasbourg, Partenaires INRAE, Géoazur (GEOAZUR 7329), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), THALES, Université de Namur [Namur] (UNamur), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Universität Heidelberg [Heidelberg] = Heidelberg University-Universität Heidelberg [Heidelberg] = Heidelberg University, Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), THALES [France], Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Universidad de Cantabria, Gaia Collaboration, Planetary-system research, Department of Physics, Particle Physics and Astrophysics, Astronomy, and ITA

Subjects
trigonometric parallaxes, Solar neighborhood, Stars: luminosity function, mass function, Astronomy, Astrophysics, 01 natural sciences, luminosity function, mass function [Stars], Astronomi, astrofysik och kosmologi, luminosity: mass function [Stars], Astronomy, Astrophysics and Cosmology, MAIN-SEQUENCE, Hertzsprung-Russell-diagram, 010303 astronomy & astrophysics, Stars:low-mass brown-dwarfs, wide binaries, Physics, education.field_of_study, north galactic pole, Astrophysics::Instrumentation and Methods for Astrophysics, Astrometry, BROWN DWARF, Astrophysics - Solar and Stellar Astrophysics, mass function, NORTH GALACTIC POLE, Physical Sciences, symbols, CIRCULAR-VELOCITY CURVE, Halo, astro-ph.SR, Hertzsprung–Russell diagram, stars: luminosity function, astro-ph.GA, Posterior probability, Population, main-sequence, Luminosity-Function, FOS: Physical sciences, Mass-Function, Astronomy & Astrophysics, Computer Science::Digital Libraries, Photometry (optics), DWARF LUMINOSITY-FUNCTION, dwarf luminosity-function, sky-survey, symbols.namesake, Settore FIS/05 - Astronomia e Astrofisica, luminosity function [stars], low-mass [Stars], 0103 physical sciences, Stars: luminosity: mass function, Stars: low-mass, WHITE-DWARFS, education, Solar and Stellar Astrophysics (astro-ph.SR), brown dwarf, catalogs, astrometry, Hertzsprung-Russell and C-M diagrams, stars: low-mass, solar neighborhood, Astrophysics - Astrophysics of Galaxies, SKY-SURVEY, white-dwarfs, Science & Technology, 010308 nuclear & particles physics, Luminosity function, White dwarf, TRIGONOMETRIC PARALLAXES, Astronomy and Astrophysics, Low-mass, 115 Astronomy, Space science, WIDE BINARIES, Stars, Physics::History of Physics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), solar-neighborhood, Catalogs, circular-velocity curve, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Aims. We produce a clean and well-characterised catalogue of objects within 100 pc of the Sun from the Gaia Early Data Release 3. We characterise the catalogue through comparisons to the full data release, external catalogues, and simulations. We carry out a first analysis of the science that is possible with this sample to demonstrate its potential and best practices for its use., Methods. Theselection of objects within 100 pc from the full catalogue used selected training sets, machine-learning procedures, astrometric quantities, and solution quality indicators to determine a probability that the astrometric solution is reliable. The training set construction exploited the astrometric data, quality flags, and external photometry. For all candidates we calculated distance posterior probability densities using Bayesian procedures and mock catalogues to define priors. Any object with reliable astrometry and a non-zero probability of being within 100 pc is included in the catalogue., Results. We have produced a catalogue of 331 312 objects that we estimate contains at least 92% of stars of stellar type M9 within 100 pc of the Sun. We estimate that 9% of the stars in this catalogue probably lie outside 100 pc, but when the distance probability function is used, a correct treatment of this contamination is possible. We produced luminosity functions with a high signal-to-noise ratio for the main-sequence stars, giants, and white dwarfs. We examined in detail the Hyades cluster, the white dwarf population, and wide-binary systems and produced candidate lists for all three samples. We detected local manifestations of several streams, superclusters, and halo objects, in which we identified 12 members of Gaia Enceladus. We present the first direct parallaxes of five objects in multiple systems within 10 pc of the Sun., Conclusions. We provide the community with a large, well-characterised catalogue of objects in the solar neighbourhood. This is a primary benchmark for measuring and understanding fundamental parameters and descriptive functions in astronomy.

Published
2021
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2. Ensemble asteroseismology of pulsating B-type stars in NGC 6910

Author

S. Saesen, V. Van Helshoecht, M. Stęślicki, Przemysław Walczak, D. Moździerski, Karolien Lefever, Xiao-Jun Jiang, Jian-Ning Fu, G. Kopacki, A. Narwid, Jason Jackiewicz, Fabien Carrier, Clio Gielen, J. Telting, P. Bruś, P. Śródka, M. Vučković, J. Vanautgaerden, Thierry Morel, E. Zahajkiewicz, Tijl Verhoelst, Leen Decin, Conny Aerts, Andrzej Pigulski, Z. Kołaczkowski, G. Michalska, and C. Zhang

Subjects
stars, Opacity, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, open clusters and associations, BETA-CEPHEI, INSTABILITY, FOS: Physical sciences, MODE-IDENTIFICATION, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, asteroseismology, Astronomy & Astrophysics, 01 natural sciences, Asteroseismology, Computer Science::Digital Libraries, Photometry (optics), VARIABLE-STARS, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, early-type, PHOTOMETRY, SURFACE GRAVITY, individual, 010306 general physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, YOUNG OPEN CLUSTERS, Science & Technology, SPECTROSCOPIC IDENTIFICATION, EFFECTIVE TEMPERATURE, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Physics::History of Physics, Stars, STELLAR, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Physical Sciences, oscillations, NGC 6910, Astrophysics::Earth and Planetary Astrophysics, Low Mass, Open cluster, fundamental parameters
Abstract

Asteroseismology offers the possibility of probing stellar interiors and testing evolutionary and seismic models. Precise photometry and spectroscopy obtained during multi-site campaigns on young open clusters allows discovering rich samples of pulsating stars and using them in a simultaneous seismic modelling called ensemble asteroseismology. The aim of this study is to obtain the age of the open cluster NGC 6910 by means of ensemble asteroseismology of the early-type pulsating members, to derive their stellar parameters, and to classify the excited modes. We used time-series analysis, performed photometric and spectroscopic mode identification, and calculated grids of evolutionary and seismic models to apply the procedure of ensemble asteroseismology for nine pulsating members of NGC 6910. With two iterations of the procedure of ensemble asteroseismology applied to nine pulsating stars we derived an age of 10.6$^{+0.9}_{-0.8}$ Myr for NGC 6910. Of the nine pulsating stars examined in the paper, eight are $\beta$ Cep stars, including three that are hybrid $\beta$ Cep and slowly pulsating B-type (SPB) pulsators, and one is an SPB star. Interestingly, the least massive $\beta$ Cep star, NGC 6910-38, has a mass of about 5.6 M$_\odot$. The present theory does not predict unstable $p$ modes in B-type stars with such a low mass. The $g$ modes with relatively high frequencies ($>3.5$ d$^{-1}$), observed in three members of the cluster, are also stable according to seismic modelling. Both findings pose a challenge for theoretical calculations and prompt a revision of the opacities. The procedure of ensemble asteroseismology was found to be successful for NGC 6910 and $\chi$ Per on the basis of pulsating B-type stars and can therefore be applied to other young open clusters that are rich in such stars., Comment: 22 pages, 24 figures. Caution: arXiv abstract is shorter than in the article

Published
2019
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3. Europium as a lodestar: diagnosis of radiogenic heat production in terrestrial exoplanets

Author

Stephen J. Mojzsis, Sascha P. Quanz, Haiyang Wang, and Thierry Morel

Subjects
Physics, education.field_of_study, Radiogenic nuclide, 010504 meteorology & atmospheric sciences, Population, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Exoplanet, Mantle (geology), Mantle convection, Space and Planetary Science, Planet, 0103 physical sciences, Terrestrial planet, education, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

Context. Long-lived radioactive nuclides, such as 40K, 232Th, 235U, and 238U, contribute to persistent heat production in the mantle of terrestrial-type planets. As refractory elements, the concentrations of Th and U in a terrestrial exoplanet are implicitly reflected in the photospheric abundances of the stellar host. However, a robust determination of these stellar abundances is difficult in practice owing to the general paucity and weakness of the relevant spectral features. Aims. We draw attention to the refractory, r-process element europium, which may be used as a convenient and practical proxy for the population analysis of radiogenic heating in exoplanetary systems. Methods. As a case study, we present a determination of Eu abundances in the photospheres of α Cen A and B with high-resolution HARPS spectra and a strict line-by-line differential analysis. To first order, the measured Eu abundances can be converted into the abundances of 232Th, 235U, and 238U with observational constraints, while the abundance of 40K is approximated independently with a Galactic chemical evolution model. Results. Our determination shows that europium is depleted with respect to iron by ~0.1 dex and to silicon by ~0.15 dex compared to solar in the two binary components. The loci of α Cen AB at the low-ends of both [Eu/Fe] and [Eu/Si] distributions of a large sample of FGK stars further suggest significantly lower potential of radiogenic heat production in any putative terrestrial-like planet (i.e. α-Cen-Earth) in this system compared to that in rocky planets (including our own Earth) that formed around the majority of these Sun-like stars. Based on our calculations of the radionuclide concentrations in the mantle and assuming the mantle mass to be the same as that of our Earth, we find that the radiogenic heat budget in an α-Cen-Earth is 73.4−6.9+8.3 TW upon its formation and 8.8−1.3+1.7 TW at the present day, which is 23 ± 5% and 54 ± 5% lower than that in the Hadean Earth (94.9 ± 5.5 TW) and in the modern Earth (19.0 ± 1.1 TW), respectively. Conclusions. As a consequence, mantle convection in an α-Cen-Earth is expected to be overall weaker than that of Earth (assuming other conditions are the same), and thus such a planet would be less geologically active, suppressing its long-term potential to recycle its crust and volatiles. With Eu abundances being available for a large sample of Sun-like stars, the proposed approach can extend our ability to predict the nature of other rocky worlds that can be tested by future observations.

Published
2020
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4. Gaia Data Release 2

Author

H. E. Huckle, F. Riclet, R. Buzzi, D. J. Marshall, Deborah Busonero, Michael Davidson, C Boeche, Sergio Messina, F. X. Pineau, G. Jasniewicz, L. Balaguer-Núñez, C. A. L. Bailer-Jones, L. Chaoul, J. L. Halbwachs, D. Teyssier, A. F. Lanza, Alberto Vecchiato, Shay Zucker, Francois Taris, Conny Aerts, L. Pulone, Mario Gai, L. M. Sarro, Frédéric Arenou, Á. L. Juhász, Alessandro Bressan, Joao Alves, Morgan Fouesneau, David Hobbs, Yves Fremat, L. Ruiz-Dern, A. Hutton, Sofia Randich, Gerry Gilmore, D. Garabato, Leanne P. Guy, J. González-Núñez, M. Weiler, H. Steidelmüller, D. de Martino, M. A. Álvarez, Vincenzo Ripepi, G. Gracia-Abril, Uwe Lammers, P. de Laverny, G. Sadowski, Nicolas Mary, Bengt Edvardsson, Laszlo Szabados, Łukasz Wyrzykowski, David Barrado, Alberto Cellino, Damien Ségransan, T Roegiers, Olivier Wertz, A. Recio-Blanco, Sergei A. Klioner, J. Durán, A. Panahi, A. Karampelas, Alex Lobel, J.-L. Bassilana, H. Voss, Sven Zschocke, A. Bombrun, F. De Angeli, Toni Santana-Ros, J. C. Segovia, D. Vicente, S. Blanco-Cuaresma, A. G. Butkevich, M. Riello, Amina Helmi, J. Bakker, J. Souchay, A. Kewley, R Alvarez, Daniel Hestroffer, Sergey E. Koposov, Tsevi Mazeh, Maria Süveges, F. F. Suess, P. Drazinos, B. Holl, H. Ziaeepour, T. Wevems, Eva Sciacca, P. Esquej, A. Gueguen, J. Heu, R. Geyer, J. Fernández-Hernández, E. Licata, Laurent Galluccio, J. Cuypers, Peter G. Jonker, Ummi Abbas, Elena Pancino, Jean Surdej, E. Anglada Varela, Michele Bellazzini, Teresa Antoja, Martin A. Barstow, László Molnár, Isabella Pagano, E. Solano, E. Brugaletta, P. Koubsky, Paolo Tanga, Alberto Krone-Martins, M. Clotet, Nigel Hambly, R. L. Smart, Paolo Giacobbe, Simchon Faigler, G. Giuffrida, Aldo Dell'Oro, Yveline Lebreton, Stefano Bertone, Mario G. Lattanzi, Paul S. Barklem, D. Tapiador, Patrick Charlot, A. H. Andrei, Luciano Nicastro, S. Managau, Lorenzo Rimoldini, Mario Di Martino, Paolo Montegriffo, A. Abreu Aramburu, O. Marchal, Marcella Marconi, K. Janßen, K. Findeisen, Xavier Luri, A. Berihuete, M. Schultheis, P. Di Matteo, R. Mor, C. Barata, A. Mora, W. van Reeven, Mikael Granvik, M. Barros, Carine Babusiaux, A. G. A. Brown, Mark Taylor, Y. Le Fustec, T. Lebzelter, Nami Mowlavi, O. L. Creevey, F. Barblan, Thierry Morel, Timo Prusti, A. Riva, S. Girona, S. Liao, Viktor Votruba, Frédéric Royer, Laurent Chemin, G. Altavilla, A. M. Piersimoni, Davide Massari, Marco Delbo, S. Diakite, V. Valette, N. Bach, H. Lenhardt, André Moitinho, Christophe Barache, S. Galleti, Michał Pawlak, A. Yoldas, Harry Enke, Rosanna Sordo, A. Jean-Antoine-Piccolo, Patrice David, Giacomo Cannizzaro, W. Löffler, J. Torra, Tristan Cantat-Gaudin, Marc Audard, D. Katz, Jose M Hernandez, Gijs Nelemans, S. Ragaini, P. Osborne, D. Terrett, A. J. Falcão, D. L. Harrison, G. Plum, R. G. Mann, Ulrike Heiter, Carla Cacciari, Gal Matijevic, J. M. Petit, A. Titarenko, Despina Hatzidimitriou, Juan Zorec, Angela Bragaglia, Nicholas Rowell, Annie C. Robin, Mario David, Tri L. Astraatmadja, Giovanni Comoretto, F. Julbe, Derek W. Morris, R. Drimmel, F. García-Sedano, A. Dapergolas, L. Noval, Mike Smith, Grigori Fedorets, H. Palacin, L. Bramante, D. Molina, Jesus Salgado, C. Dolding, M. Vaillant, Daniel Michalik, H. I. Siddiqui, Minia Manteiga, P. J. Richards, D. Barbato, A. Fonti, Raphael Guerra, J. J. González-Vidal, E. del Pozo, Mariateresa Crosta, M. Žerjal, F. Torra Clotet, C. Diener, M. Hauser, G. Walmsley, Sonia Nieto, I. Bellas-Velidis, T. Boch, Antonella Vallenari, M. Segol, S. Voutsinas, F. Leroux, A. F. Mulone, Pierre Fernique, Céline Reylé, P. Panuzzo, W. Hofmann, S. Bouquillon, F. Crifo, S. Cowell, Ana Ulla, Benoit Carry, C. Ordenovic, F. Pailler, E. Utrilla, Dimitri Pourbaix, A. Hypki, Stefan Jordan, T. Carlucci, Gráinne Costigan, Alfred Castro-Ginard, C. Fabre, C. Crowley, R. Borrachero, Sébastien Lambert, J. H. J. de Bruijne, D. W. Evans, C. Turon, T. Brüsemeister, F. De Luise, R. Haigron, Carme Jordi, G. Marschalkó, C. von Essen, C. Pagani, Katrien Kolenberg, M. van Leeuwen, N. R. Millar, Gisella Clementini, A. de Torres, Ugo Becciani, S. Marinoni, Geraldine Bourda, A. F. Silva, L. Eyer, Misha Haywood, C. Fabricius, Krzysztof Nienartowicz, Miguel García-Torres, S. Regibo, P. Gavras, Gábor Marton, Elisa Distefano, A. Guerrier, H. E. P. Lindstrøm, N. A. Walton, N. Brouillet, G. Eynard Bontemps, T. A. Lister, F. A. Jansen, Ruth Carballo, Steve Vogt, J. M. Carrasco, G. Mantelet, M. Romero-Gómez, Ramachrisna Teixeira, Kjell Eriksson, A. Kochoska, Johannes Sahlmann, Joakim Klar, R. Gutiérrez-Sánchez, Ilaria Musella, L. Palaversa, Karri Muinonen, J. M. Martín-Fleitas, T. Sagristà Sellés, Marco Castellani, Y. Viala, Laia Casamiquela, R. Messineo, Eduard Masana, R. de Souza, H. Stoev, L. Siltala, B. Frezouls, E. Szegedi-Elek, Tomaz Zwitter, G. Kordopatis, C. Ducourant, Tatiana Muraveva, P. Burgess, J. De Ridder, E. Salguero, A. Burlacu, I-C. Shih, U. Stampa, V. Icardi, Iain A. Steele, Alessandro Sozzetti, M. Kontizas, Roberto Molinaro, F. Solitro, H. E. Delgado, G. Holland, J.-B. Lavigne, Andreas Korn, M. Biermann, E. Fraile, M. Fabrizio, Francesca Figueras, R. Blomme, P. Teyssandier, Elisabetta Caffau, G. Busso, Maroussia Roelens, Maarten A. Breddels, Simon Hodgkin, Luciana Bianchi, Olivier Bienaymé, Silvio Leccia, C. Le Poncin-Lafitte, Morgan Fraser, M. Ramos-Lerate, M. Gomes, N. Cheek, J. Osinde, Jérôme Berthier, Kevin Benson, Christos Siopis, P. Balm, E. Gosset, Yassine Damerdji, Richard I. Anderson, C. Zurbach, Jonas Debosscher, G. Cocozza, William O'Mullane, Andrea Chiavassa, F.E. van Leeuwen, Diego Bossini, Federica Spoto, G. Jevardat de Fombelle, Nicoletta Sanna, J. Guiraud, G. Tauran, K. W. Smith, E. Poujoulet, Mark Cropper, Z. Kostrzewa-Rutkowska, F. Glass, J. Gerssen, Thomas Hilger, C.A. Stephenson, D. Ordóñez-Blanco, Andrej Prsa, M. Sarasso, E. Kontizas, Luciana Federici, Paul J. McMillan, Nicolas Rambaux, Ludovic Delchambre, M. Garcia-Reinaldos, T. Pauwels, M. Farràs Casas, S. Bartholomé Muñoz, E. Livanou, E. Van Hemelryck, Roberto Morbidelli, R. Kohley, A. Garofalo, Jovan Veljanoski, Jon Marchant, Jordi Portell, Ulrich Bastian, M. Lopez, Bernardino Arcay, H. Savietto, Alessandro Spagna, A. C. Lanzafame, Beatrice Bucciarelli, C. Panem, Carlos Dafonte, Y. Lasne, P. Sartoretti, E. Racero, William Thuillot, A. Gavel, J. Castañeda, Gaetano Valentini, A. Rivard, E. Poggio, N. Garralda, R. De March, S. G. Baker, S. Accart, M. Altmann, F. Filippi, George M. Seabroke, F. Thévenin, A. van Elteren, Emese Plachy, Lennart Lindegren, Isabelle Lecoeur-Taïbi, Guy Rixon, S Uzzi, M Vaschetto, Francois Mignard, E. Antiche, P. M. Marrese, N. Leclerc, Caroline Soubiran, Rene Andrae, A. Delgado, and Rossella Cancelliere

Subjects
Physics, 010504 meteorology & atmospheric sciences, Astronomy, Astronomy and Astrophysics, galaxies: dwarf, Astrophysics, Astrometry, globular clusters: general, 01 natural sciences, Settore FIS/05 - Astronomia e Astrofisica, Space and Planetary Science, 0103 physical sciences, Local Group, astrometry, High Energy Physics, Galaxy: kinematics and dynamics, astrometry, globular clusters: general, galaxies: dwarf, Local Group, errata, addenda, Galaxy: kinematics and dynamics, addenda, 010303 astronomy & astrophysics, Data release, Astrophysique, errata, 0105 earth and related environmental sciences
Abstract

0, info:eu-repo/semantics/published

Published
2020
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5. The chemical composition of α Centauri AB revisited

Author

Thierry Morel

Subjects
Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Stars, Space and Planetary Science, Planet, Abundance (ecology), Stellar physics, 0103 physical sciences, Terrestrial planet, 010303 astronomy & astrophysics, Chemical composition, Visual binary
Abstract

The two solar-like stars α Cen A and B have long served as cornerstones for stellar physics in virtue of their immediate proximity, association in a visual binary, and masses that bracket that of the Sun. The recent detection of a terrestrial planet in the cool, suspected tertiary Proxima Cen now makes the system also of prime interest in the context of planetary studies. It is therefore of fundamental importance to tightly constrain the properties of the individual stellar components. We present a fully self-consistent, line-by-line differential abundance analysis of α Cen AB based on high-quality HARPS data. Various line lists are used and analysis strategies implemented to improve the reliability of the results. Abundances of 21 species with a typical precision of 0.02–0.03 dex are reported. We find that the chemical composition of the two stars is not scaled solar (e.g. Na and Ni excess, depletion of neutron-capture elements), but that their patterns are strikingly similar, with a mean abundance difference (A – B) with respect to hydrogen of –0.01 ± 0.04 dex. Much of the scatter may be ascribed to physical effects that are not fully removed through a differential analysis because of the mismatch in parameters between the two components. We derive an age for the system from abundance indicators (e.g. [Y/Mg] and [Y/Al]) that is slightly larger than solar and in agreement with most asteroseismic results. Assuming coeval formation for the three components belonging to the system, this implies an age of about ~6 Gyrs for the M dwarf hosting the terrestrial planet Proxima Cen b. After correction for Galactic chemical evolution effects, we find a trend between the abundance ratios and condensation temperature in α Cen A akin to that of the Sun. However, taking this finding as evidence for the sequestration of rocky material locked up in planets may be premature given that a clear link between the two phenomena remains to be established. The similarity between the abundance pattern of the binary components argues against the swallowing of a massive planet by one of the stars after the convective zones have shrunk to their present-day sizes.

Published
2018
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6. New insights into the nature of the peculiar star θ Carinae

Author

Maryline Briquet, S. Hubrig, Julian Gonzalez, P. De Cat, Thierry Morel, and Markus Schoeller

Subjects
Physics, Orbital elements, Thermodynamic equilibrium, Astrophysics (astro-ph), FOS: Physical sciences, Balmer series, Astronomy and Astrophysics, Astrophysics, Spectral line, Magnetic field, symbols.namesake, Stars, Amplitude, Space and Planetary Science, symbols, Astrophysics::Solar and Stellar Astrophysics, Binary system, Astrophysics::Galaxy Astrophysics
Abstract

We acquired high resolution spectroscopic and low resolution spectropolarimetric observations to achieve the following goals: a) to improve the orbital parameters to allow a more in-depth discussion on the possibility of mass transfer in the binary system, b) to carry out a non-local thermodynamic equilibrium (NLTE) abundance analysis, and c) to search for the presence of a magnetic field. The study of the radial velocities using CORALIE spectra allowed us to significantly improve the orbital parameters. A comparative NLTE abundance analysis was undertaken for theta Car and two other early B-type stars with recently detected magnetic fields, tau Sco and xi^1 CMa. The analysis revealed significantly different abundance patterns: a one-order-of-magnitude nitrogen overabundance and carbon depletion was found in theta Car, while the oxygen abundance is roughly solar. For the stars xi^1 CMa and tau Sco the carbon abundance is solar and, while an N excess is also detected, it is of much smaller amplitude (0.4-0.6dex). Such an N overabundance is typical of the values already found for other slowly-rotating (magnetic) B-type dwarfs. For theta Car, we attribute instead the chemical peculiarities to a past episode of mass transfer between the two binary components. The results of the search for a magnetic field using FORS1 at the VLT consisting of 26 measurements over a time span of ~1.2h are rather inconclusive: only few measurements have a significance level of 3sigma. Although we detect a periodicity of the order of ~8.8min in the dataset involving the measurements on all hydrogen Balmer lines with the exception of the Halpha and Hbeta lines, these results have to be confirmed by additional time-resolved magnetic field observations., 10 pages, 9 figures, 6 tables, accepted for publication in A&A

Published
2008
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7. Spectroscopic determination of photospheric parameters and chemical abundances of 6 K-type stars

Author

Fabio Favata, Thierry Morel, Laura Affer, Giuseppina Micela, and Jorge Sanz-Forcada

Subjects
Physics, Stars, Space and Planetary Science, Subgiant, Metallicity, Astronomy and Astrophysics, Astrophysics, Effective temperature, Surface gravity, Equivalent width, Abundance of the chemical elements, Line (formation)
Abstract

High resolution, high -S /N- ratio optical spectra have been obtained for a sample of 6 K-type dwarf and subgiant stars, and have been analysed with three different LTE methods in order to derive detailed photospheric parameters and abun- dances and to compare the characteristics of analysis techniques. The results have been compared with the aim of determining the most robust method to perform complete spectroscopic analyses of K-type stars, and in this perspective the present work must be considered as a pilot study. In this context we have determined the abundance ratios with respect to iron of several elements. In the first method the photospheric parameters (Teff ,l ogg ,a ndξ) and metal abundances are derived using measured equivalent widths and Kurucz LTE model atmospheres as input for the MOOG software code. The analysis proceeds in an iterative way, and relies on the excitation equilibrium of the Fe  lines for determining the effective temperature and microtur- bulence, and on the ionization equilibrium of the Fe  and Fe  lines for determining the surface gravity and the metallicity. The second method follows a similar approach, but discards the Fe  low excitation potential transitions (which are potentially affected by non-LTE effects) from the initial line list, and relies on the B − V colour index to determine the temperature. The third method relies on the detailed fitting of the 6162 A Ca  line to derive the surface gravity, using the same restricted line list as the second method. Methods 1 and 3 give consistent results for the program stars; in particular the comparison between the results obtained shows that the Fe  low-excitation potential transitions do not appear significantly affected by non-LTE effects (at least for the subgiant stars), as suggested by the good agreement of the atmospheric parameters and chemical abundances derived. The second method leads to systematically lower Teff and log g values with respect to the first one, and a similar trend is shown by the chemical abundances (with the exception of the oxygen abundance). These differences, apart from residual non-LTE effects, may be a consequence of the colour-Teff scale used. The α-elements have abundance ratios consistent with the solar values for all the program stars, as expected for "normal" disk stars. The first method appears to be the most reliable one, as it is self-consistent, it always leads to convergent solutions and the results obtained are in good agreement with previous determinations in the literature.

Published
2005
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8. The nature of the high Galactic latitude O-star HD 93521: new results from X-ray and optical spectroscopy

Author

Matthieu Palate, Thierry Morel, and Grégor Rauw

Subjects
Physics, Star formation, Metallicity, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galactic plane, Surface gravity, Subdwarf, Stars, Supernova, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, O-type star
Abstract

Owing to its unusual location and its isolation, the nature of the high Galactic latitude O9.5Vp object HD93521 is still uncertain. We have collected X-ray and optical observations to characterize the star and its surroundings. X-ray images and spectra are analyzed to search for traces of a recent star formation event around HD93521 and to search for the signature of a possible compact companion. Optical echelle spectra are analysed with plane-parallel model atmosphere codes, assuming either a spherical star or a gravity darkened rotationally flattened star, to infer the effective temperature and surface gravity, and to derive the He, C, N and O abundances of HD93521. The X-ray images reveal no traces of a population of young low-mass stars coeval with HD93521. The X-ray spectrum of HD93521 is consistent with a normal late O-type star although with subsolar metallicity. No trace of a compact companion is found in the X-ray data. In the optical spectrum, He and N are found to be overabundant, in line with the effect of rotational mixing in this very fast rotator, whilst C and O are subsolar. A critical comparison with the properties of subdwarf OB stars, indicates that, despite some apparent similarities, HD93521 does not belong to this category. Despite some ambiguities on the runaway status of the star, the most likely explanation is that HD93521 is a Population I massive O-type star that was ejected from the Galactic plane either through dynamical interactions or a result of a supernova event in a binary system., Accepted for publication in Astronomy & Astrophysics

Published
2012
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9. Gravito-inertial and pressure modes detected in the B3 IV CoRoT target HD 43317

Author

M. Auvergne, W. Zima, A. Baglin, E. Michel, Péter Pápics, M. Hareter, R. Samadi, Pieter Degroote, Frédéric Baudin, C. Catala, E. Niemczura, Maryline Briquet, Monica Rainer, Thierry Morel, A. Tkatchenko, Conny Aerts, E. Poretti, INAF - Osservatorio Astronomico di Brera (OAB), Istituto Nazionale di Astrofisica (INAF), Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Université de Liège, Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
oscillations [stars], stars, catalog, Inertial frame of reference, photometry, Astronomy, individual: hd 43317 [stars], nonradial pulsation, stellar parameters, FOS: Physical sciences, asteroseismology, Astrophysics, STRIPS, 01 natural sciences, Instability, Spectral line, law.invention, Photometry (optics), law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Spectroscopy, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Light curve, abundances [stars], Stars, Astrophysics - Solar and Stellar Astrophysics, variables: general [stars], Space and Planetary Science, rotation [stars], ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, identification, chemical-composition, differential rotation, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], moment method
Abstract

Context. OB stars are important building blocks of the Universe, but we have only a limited sample of them well understood enough from an asteroseismological point of view to provide feedback on the current evolutionary models. Our study adds one special case to this sample, with more observational constraints than for most of these stars. Aims. Our goal is to analyse and interpret the pulsational behaviour of the B3 IV star HD 43317 using the CoRoT light curve along with the ground-based spectroscopy gathered by the Harps instrument. This way we continue our efforts to map the Beta Cep and SPB instability strips. Methods. We used different techniques to reveal the abundances and fundamental stellar parameters from the newly-obtained high-resolution spectra. We used various time-series analysis tools to explore the nature of variations present in the light curve. We calculated the moments and used the pixel-by-pixel method to look for line profile variations in the high-resolution spectra. Results. We find that HD 43317 is a single fast rotator (v_rot ~ 50% v_crit) and hybrid SPB/Beta Cep-type pulsator with Solar metal abundances. We interpret the variations in photometry and spectroscopy as a result of rotational modulation connected to surface inhomogeneities, combined with the presence of both g and p mode pulsations. We detect a series of ten consecutive frequencies with an almost constant period spacing of 6339 s as well as a second shorter sequence consisting of seven frequencies with a spacing of 6380 s. The dominant frequencies fall in the regime of gravito-inertial modes., Accepted for publication in Astronomy and Astrophysics on 21/03/2012, 13 pages, 10 figures, 6 tables

Published
2012
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