Search

Your search keyword '"Baudin, F"' showing total 17 results
Start Over Author "Baudin, F" Topic astrophysics::earth and planetary astrophysics
17 results on '"Baudin, F"'

1. Young [$��$/Fe]-enhanced stars discovered by CoRoT and APOGEE: What is their origin?

Author

Chiappini, C., Anders, F., Rodrigues, T. S., Miglio, A., Montalban, J., Mosser, B., Girardi, L., Valentini, M., Noels, A., Morel, T., Minchev, I., Steinmetz, M., Santiago, B. X., Schultheis, M., Martig, M., da Costa, L. N., Maia, M. A. G., Prieto, C. Allende, Peralta, R. de Assis, Hekker, S., Theme��l, N., Kallinger, T., Garcia, R. A., Mathur, S., Baudin, F., Beers, T. C., Cunha, K., Harding, P., Holtzman, J., Majewski, S., Meszaros, Sz., Nidever, D., Pan, K., Schiavon, R. P., Shetrone, M. D., Schneider, D. P., and Stassun, K.

Subjects
Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

We report the discovery of a group of apparently young CoRoT red-giant stars exhibiting enhanced [alpha/Fe] abundance ratios (as determined from APOGEE spectra) with respect to Solar values. Their existence is not explained by standard chemical evolution models of the Milky Way, and shows that the chemical-enrichment history of the Galactic disc is more complex. We find similar stars in previously published samples for which isochrone-ages could be robustly obtained, although in smaller relative numbers, which could explain why these stars have not received prior attention. The young [alpha/Fe]-rich stars are much more numerous in the CoRoT-APOGEE (CoRoGEE) inner-field sample than in any other high-resolution sample available at present, as only CoRoGEE can explore the inner-disc regions and provide ages for its field stars. The kinematic properties of the young [$��$/Fe]-rich stars are not clearly thick-disc like, despite their rather large distances from the Galactic mid-plane. Our tentative interpretation of these and previous intriguing observations in the Milky Way is that these stars were formed close to the end of the Galactic bar, near corotation -- a region where gas can be kept inert for longer times, compared to other regions shocked more frequently by the passage of spiral arms. Moreover, that is where the mass return from older inner-disc stellar generations should be maximal (according to an inside-out disc-formation scenario), further diluting the in-situ gas. Other possibilities to explain these observations (e.g., a recent gas-accretion event) are also discussed., Letter in press in Astronomy and Astrophysics (5 pages, 4 figures + 2 pages Appendix)

Published
2015
Full Text
View/download PDF

2. The PLATO 2.0 mission

Author

Rauer, H., Catala, C., Aerts, C., Appourchaux, T., Benz, W., Brandeker, A., Christensen-Dalsgaard, J., Deleuil, M., Gizon, L., Goupil, M. -J., G��del, M., Janot-Pacheco, E., Mas-Hesse, M., Pagano, I., Piotto, G., Pollacco, D., Santos, N. C., Smith, A., C., J., Su��rez, Szab��, R., Udry, S., Adibekyan, V., Alibert, Y., Almenara, J. -M., Amaro-Seoane, P., Eiff, M. Ammler-von, Asplund, M., Antonello, E., Ball, W., Barnes, S., Baudin, F., Belkacem, K., Bergemann, M., Bihain, G., Birch, A. C., Bonfils, X., Boisse, I., Bonomo, A. S., Borsa, F., Brand��o, I. M., Brocato, E., Brun, S., Burleigh, M., Burston, R., Cabrera, J., Cassisi, S., Chaplin, W., Charpinet, S., Chiappini, C., Church, R. P., Csizmadia, Sz., Cunha, M., Damasso, M., Davies, M. B., Deeg, H. J., D��az, R. F., Dreizler, S., Dreyer, C., Eggenberger, P., Ehrenreich, D., Eigm��ller, P., Erikson, A., Farmer, R., Feltzing, S., Fialho, F. de Oliveira, Figueira, P., Forveille, T., Fridlund, M., Garc��a, R. A., Giommi, P., Giuffrida, G., Godolt, M., da Silva, J. Gomes, Granzer, T., Grenfell, J. L., Grotsch-Noels, A., G��nther, E., Haswell, C. A., Hatzes, A. P., H��brard, G., Hekker, S., Helled, R., Heng, K., Jenkins, J. M., Johansen, A., Khodachenko, M. L., Kislyakova, K. G., Kley, W., Kolb, U., Krivova, N., Kupka, F., Lammer, H., Lanza, A. F., Lebreton, Y., Magrin, D., Marcos-Arenal, P., Marrese, P. M., Marques, J. P., Martins, J., Mathis, S., Mathur, S., Messina, S., Miglio, A., Montalban, J., Montalto, M., Monteiro, M. J. P. F. G., Moradi, H., Moravveji, E., Mordasini, C., Morel, T., Mortier, A., Nascimbeni, V., Nelson, R. P., Nielsen, M. B., Noack, L., Norton, A. J., Ofir, A., Oshagh, M., Ouazzani, R. -M., P��pics, P., Parro, V. C., Petit, P., Plez, B., Poretti, E., Quirrenbach, A., Ragazzoni, R., Raimondo, G., Rainer, M., Reese, D. R., Redmer, R., Reffert, S., Rojas-Ayala, B., Roxburgh, I. W., Salmon, S., Santerne, A., Schneider, J., Schou, J., Schuh, S., Schunker, H., Silva-Valio, A., Silvotti, R., Skillen, I., Snellen, I., Sohl, F., Sousa, S. G., Sozzetti, A., Stello, D., Strassmeier, K. G., ��vanda, M., Szab��, Gy. M., Tkachenko, A., Valencia, D., van Grootel, V., Vauclair, S. D., Ventura, P., Wagner, F. W., Walton, N. A., Weingrill, J., Werner, S. C., Wheatley, P. J., Zwintz, K., DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), 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, 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), Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Stockholm University, Stellar Astrophysics Centre [Aarhus] (SAC), Aarhus University [Aarhus], Department of Palaeontology, National Institutes of Health [Bethesda] (NIH)-The Natural History Museum (NHM), Laboratoire d'Informatique Avancée de Saint-Denis (LIASD), Université Paris 8 Vincennes-Saint-Denis (UP8), High Speed Networks Laboratory, Dept. of Telecommunications and Media Informatics, Budapest University of Technology and Economics [Budapest] (BME), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), Laboratoire d'astrophysique de l'observatoire de Besançon (UMR 6091) (LAOB), 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), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes - UFR Pharmacie (UGA UFRP), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Department of Physics and Astronomy [Leicester], University of Leicester, Institute for Digital Communication Joint Research Institute for Signal & Image Processing School of Engineering and Electronics - University of Edinburgh, University of Edinburgh, Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), DLR Institute of Planetary Research, German Aerospace Center (DLR), UCLA Economics, University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto = University of Porto, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Nottingham Transportation Engineering Centre, University of Nottingham, UK (UON), Thüringer Landessternwarte Tautenburg (TLS), Tel Aviv University (TAU), Center for Space and Habitability (CSH), University of Bern, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Département Langues et Culture Internationale (LCI), Université européenne de Bretagne - European University of Brittany (UEB)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, CTS/UNINOVA, Faculty of Sciences and Technology, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, School of Physics and Astronomy, University of Birmingham [Birmingham], Departamento de Física e Astronomia [Porto] (DFA/FCUP), Faculdade de Ciências da Universidade do Porto (FCUP), Universidade do Porto = University of Porto-Universidade do Porto = University of Porto, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), LAboratoire PLasma et Conversion d'Energie (LAPLACE), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Institut für Physik, Universität Rostock, Landessternwarte Königstuhl [ZAH] (LSW), Universität Heidelberg [Heidelberg] = Heidelberg University, Mécanismes adaptatifs : des organismes aux communautés (MAOAC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Historisches Institut, Universität Paderborn (UPB), Hansen Experimental Physics Lab [Stanford] (HEPL), Stanford University, Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Department of Experimental Physics, University of Szeged [Szeged], ELTE Gothard Astrophysical Observatory, Eötvös Loránd University (ELTE), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (1965 - 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, 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), Juelich Centre for Neutron Science, IFF, Forschungszentrum Juelich, Institut fuer Festkoerperforschung Juelich, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern], Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université de Genève (UNIGE), Laboratoire d'astrophysique de l'observatoire de Besançon (LAOB), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Université Grenoble Alpes (UGA), University of California-University of California, Universidade do Porto [Porto], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), European Space Agency (ESA)-European Space Agency (ESA), Tel Aviv University [Tel Aviv], Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), The Open University [Milton Keynes] (OU), Max-Planck-Institut für Sonnensystemforschung (MPS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Osaka City University Advanced Mathematical Institute (OCAMI), Osaka Media Center, Technical University of Denmark [Lyngby] (DTU), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Universität Heidelberg [Heidelberg], Muséum national d'Histoire naturelle (MNHN)-Collège de France (CdF)-Centre National de la Recherche Scientifique (CNRS), Hansen Experimental Physics Laboratory (HEPL), Stanford University [Stanford], ELTE Gao-Lendulet Research Group, Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Low Energy Astrophysics (API, FNWI), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-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)-Université Pierre et Marie Curie - Paris 6 (UPMC), Universidade do Porto, Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-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)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Osaka City university Advanced Mathematical Institute [Osaka] (OCAMI), Osaka City University (OCU), 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), 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), 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), and Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
photometry, Gas giant, 530 Physics, FOS: Physical sciences, asteroseismology, Astrophysics::Cosmology and Extragalactic Astrophysics, transit surey, Asteroseismology, INSTRUMENTAÇÃO (ASTRONOMIA), Planet, Astrophysics::Solar and Stellar Astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Seismaology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Exoplanetary science, Planetary habitability, Exoplanets, 520 Astronomy, Stellar science, Astronomy, Astronomy and Astrophysics, Planetary system, 620 Engineering, Exoplanet, Stars, exoplanets, 13. Climate action, Space and Planetary Science, Transit survey, Terrestrial planet, Astrophysics::Earth and Planetary Astrophysics, Circumstellar habitable zone, Astrophysics - Earth and Planetary Astrophysics
Abstract

PLATO 2.0 has recently been selected for ESA's M3 launch opportunity (2022/24). Providing accurate key planet parameters (radius, mass, density and age) in statistical numbers, it addresses fundamental questions such as: How do planetary systems form and evolve? Are there other systems with planets like ours, including potentially habitable planets? The PLATO 2.0 instrument consists of 34 small aperture telescopes (32 with 25 sec readout cadence and 2 with 2.5 sec candence) providing a wide field-of-view (2232 deg2) and a large photometric magnitude range (4-16 mag). It focusses on bright (4-11 mag) stars in wide fields to detect and characterize planets down to Earth-size by photometric transits, whose masses can then be determined by ground-based radial-velocity follow-up measurements. Asteroseismology will be performed for these bright stars to obtain highly accurate stellar parameters, including masses and ages. The combination of bright targets and asteroseismology results in high accuracy for the bulk planet parameters: 2%, 4-10% and 10% for planet radii, masses and ages, respectively. The planned baseline observing strategy includes two long pointings (2-3 years) to detect and bulk characterize planets reaching into the habitable zone (HZ) of solar-like stars and an additional step-and-stare phase to cover in total about 50% of the sky. PLATO 2.0 will observe up to 1,000,000 stars and detect and characterize hundreds of small planets, and thousands of planets in the Neptune to gas giant regime out to the HZ. It will therefore provide the first large-scale catalogue of bulk characterized planets with accurate radii, masses, mean densities and ages. This catalogue will include terrestrial planets at intermediate orbital distances, where surface temperatures are moderate. Coverage of this parameter range with statistical numbers of bulk characterized planets is unique to PLATO 2.0., Comment: 63 pages, 17 figures, submitted to Experimental Astronomy (ExA)

Published
2014

3. Differential asteroseismic study of seismic twins observed by CoRoT

Author

Ozel, N., Mosser, B., Dupret, M. A., Bruntt, H., Barban, C., Deheuvels, S., García, R. A., Michel, E., Samadi, R., Baudin, F., Mathur, S., Régulo, C., Auvergne, M., Catala, C., Morel, Pierre, Pichon, B., 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, 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), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
techniques: photometric, Astrophysics::Solar and Stellar Astrophysics, stars: individual: HD 181420, Astrophysics::Earth and Planetary Astrophysics, stars: evolution, asteroseismology, stars: interiors, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], stars: individual: HD 175272
Abstract

International audience; Context. The CoRoT short asteroseismic runs give us the opportunity to observe a large variety of late-type stars through their solar-like oscillations. We report the observation and modeling of the F5V star HD 175272.Aims. Our aim is to define a method for extracting as much information as possible from a noisy oscillation spectrum. Methods. We followed a differential approach that consists of using a well-known star as a reference to characterize another star. We used classical tools such as the envelope autocorrelation function to derive the global seismic parameters of the star. We compared HD 175272 with HD 181420 through a linear approach, because they appear to be asteroseismic twins.Results. The comparison with the reference star enables us to substantially enhance the scientific output for HD 175272. First, we determined its global characteristics through a detailed seismic analysis of HD 181420. Second, with our differential approach, we measured the difference of mass, radius and age between HD 175272 and HD 181420.Conclusions. We have developed a general method able to derive asteroseismic constraints on a star even in case of low-quality data. This method can be applied to stars with interesting properties but low signal-to-noise ratio oscillation spectrum, such as stars hosting an exoplanet or members of a binary system.

Published
2013

4. An in-depth study of HD 174966 with CoRoT photometry and HARPS spectroscopy. Large separation as a new observable for ��Sct stars

Author

Hern��ndez, A. Garc��a, Moya, A., Michel, E., Su��rez, J. C., Poretti, E., Mart��n-Ru��z, S., Amado, P. J., Garrido, R., Rodr��guez, E., Rainer, M., Uytterhoeven, K., Rodrigo, C., Solano, E., Rod��n, J. R., Mathias, P., Rolland, A., Auvergne, M., Baglin, A., Baudin, F., Catala, C., and Samadi, R.

Subjects
Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

The aim of this work was to use a multi-approach technique to derive the most accurate values possible of the physical parameters of the ��Sct star HD174966. In addition, we searched for a periodic pattern in the frequency spectra with the goal of using it to determine the mean density of the star. First, we extracted the frequency content from the CoRoT light curve. Then, we derived the physical parameters of HD174966 and carried a mode identification out from the spectroscopic and photometric observations. We used this information to look for the models fulfilling all the conditions and discussed the inaccuracies of the method because of the rotation effects. In a final step, we searched for patterns in the frequency set using a Fourier transform, discussed its origin and studied the possibility of using the periodicity to obtain information about the physical parameters of the star. A total of 185 peaks were obtained from the Fourier analysis of the CoRoT light curve, being almost all reliable pulsating frequencies. From the spectroscopic observations, 18 oscillation modes were detected and identified, and the inclination angle ($62.5^{\circ}$$^{+7.5}_{-17.5}$) and the rotational velocity of the star (142 km/s) were estimated. From the multi-colour photometric observations, 3 frequencies were detected, which correspond to the main ones in the CoRoT light curve. We looked for periodicities within the 185 frequencies and found a periodic pattern ~64 ��Hz. Using the inclination angle, the rotational velocity and an Echelle diagram, showing a double comb outside the asymptotic regime, we concluded that the periodicity corresponds to a large separation structure. The periodic pattern allowed us to discriminate models from a grid, finding that the value of the mean density is achieved with a 6% uncertainty. So, the pattern could be used as a new observable for A-F type stars., 15 pages, 10 figures, 6 tables

Published
2013
Full Text
View/download PDF

5. The underlying physical meaning of the $\nu_{\rm max}-\nu_{\rm c}$ relation

Author

Belkacem, K., Goupil, M. J., Dupret, M. A., Samadi, R., Baudin, F., Noels, A., and Mosser, B.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics
Abstract

Asteroseismology of stars that exhibit solar-like oscillations are enjoying a growing interest with the wealth of observational results obtained with the CoRoT and Kepler missions. In this framework, scaling laws between asteroseismic quantities and stellar parameters are becoming essential tools to study a rich variety of stars. However, the physical underlying mechanisms of those scaling laws are still poorly known. Our objective is to provide a theoretical basis for the scaling between the frequency of the maximum in the power spectrum ($\nu_{\rm max}$) of solar-like oscillations and the cut-off frequency ($\nu_{\rm c}$). Using the SoHO GOLF observations together with theoretical considerations, we first confirm that the maximum of the height in oscillation power spectrum is determined by the so-called \emph{plateau} of the damping rates. The physical origin of the plateau can be traced to the destabilizing effect of the Lagrangian perturbation of entropy in the upper-most layers which becomes important when the modal period and the local thermal relaxation time-scale are comparable. Based on this analysis, we then find a linear relation between $\nu_{\rm max}$ and $\nu_{\rm c}$, with a coefficient that depends on the ratio of the Mach number of the exciting turbulence to the third power to the mixing-length parameter., Comment: 8 pages, 11 figures. Accepted in A&A

Published
2011

6. CoRoT observations of O stars: diverse origins of variability

Author

Blomme, R., Briquet, M., Degroote, P., Mahy, L., Aerts, C., Cuypers, J., Godart, M., Gosset, E., Hareter, M., Montalban, J., Morel, T., Nieva, M. F., Noels, A., Oreiro, R., Poretti, E., Przybilla, N., Rainer, M., Gregor Rauw, Schiller, F., Simon-Diaz, S., Smolders, K., Ventura, P., Vučković, M., Auvergne, M., Baglin, A., Baudin, F., Catala, C., Michel, E., and Samadi, R.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

Six O-type stars were observed continuously by the CoRoT satellite during a 34.3-day run. The unprecedented quality of the data allows us to detect even low-amplitude stellar pulsations in some of these stars (HD 46202 and the binaries HD 46149 and Plaskett's star). These cover both opacity-driven modes and solar-like stochastic oscillations, both of importance to the asteroseismological modelling of O stars. Additional effects can be seen in the CoRoT light curves, such as binarity and rotational modulation. Some of the hottest O-type stars (HD 46223, HD 46150 and HD 46966) are dominated by the presence of red-noise: we speculate that this is related to a sub-surface convection zone., Comment: 5 pages, 3 figures, conference paper. To be published in "Four decades of Research on Massive Stars", Astronomical Society of the Pacific. Eds. C. Robert, N. St-Louis and L. Drissen

Published
2011
Full Text
View/download PDF

7. A quantitative analysis of stellar activity based on CoRoT photometric data

Author

Hulot, J. C., Baudin, F., Samadi, R., and Goupil, M. J.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

The CoRoT satellite has made available high precision photometric observations of a large number of stars of different spectral types. Continuous photometric time series allow the characterization of stellar microvariability in a systematic way. We determine an index indicating the level of activity, derived from photometric data, for a large sample of stars with different color temperatures. We also assess to what extent this index can be related to an estimated Rossby number for stars whose rotation period can be estimated. We also estimate a characteristic lifetime of the surface heterogeneities. Our work is based on the Fourier analysis of stellar light curves. We analyzed the Fourier power spectra of 430 selected light curves obtained by CoRoT during three observation runs. The low-frequency contribution of the stellar variability is modelled by a "generalized semi-lorentzian" profile. An activity index is derived from the fitted amplitude and width of the semi-lorentzian model. Some of the Fourier spectra exhibit a rotational modulation which enables the determination of the rotation period. In addition, a convective turnover time is derived from a grid of stellar models, so that a Rossby number can be estimated. A characteristic lifetime of the phenomena causing the observed power at low frequency is assessed from the fitted model of the power spectrum and is compared to the rotation period. Higher values of the microvariability index are observed among the coolest stars from our sample. 28 light curves show a clear rotational modulation. The estimated Rossby number of most of the observed stars with a rotational modulation is less than 1. The activity index decreases with increasing Rossby number. The quality of the CoRoT data enables the determination of the characteristic lifetime of active structures. It is shown to increase with the rotation period., Comment: second revised version submitted to A&A on April 11, 2011 10 pages, 8 figures

Published
2011
Full Text
View/download PDF

8. Red Giants observed with CoRoT

Author

Hekker, S., Ridder, J., Baudin, F., Barban, C., Carrier, F., Hatzes, A. P., Thomas Kallinger, and Weiss, W. W.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Physics::Space Physics, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

Observations of red (G-K)-giant stars with the CoRoT satellite provide unprecedented information on the stochastically excited oscillations in these stars. The long time series of nearly uninterrupted high-cadence and high-precision photometry revealed the presence of non-radial modes with long lifetimes, which opens the possibility to perform asteroseismology on these stars. Also, the large number of red giants, for which solar-like oscillations are now observed, allows for a more statistical investigation of the characteristics of solar-like oscillations in red giants., Proc. 'Stellar Pulsation: Challenges for theory and observation'; eds Joyce Ann Guzik, Paul A. Bradley; AIP Conf. Proc., Vol. 1170, pp. 127-131 (2009)

Published
2010

9. Amplitude variations of the CoRoT Be star 102719279

Author

Gutiérrez-Soto, J., Semaan, T., Garrido, R., Baudin, F., Hubert, A. -M., and Neiner, C.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

The Be star 102719279 is an interesting target observed with CoRoT during two runs, giving us the possibility to study the stability of the detected frequencies and to search for any correlation with outburts, as it was recently found in the Be star HD 49330 (Huat et al. 2009). The light curve of the star 102719279 shows fadings, multiperiodicity, stable and transient frequencies, etc. The short-term variations of the light curve are probably produced by non-radial pulsations together with some material that is ejected from the star, which produces the transient frequency. It is should be noted that the two main frequencies are synchronized and have the maximum amplitude just before the outburst., Comment: 4 pages, 4 figures, Astronomische Nachrichten, HELASIV conference, Lanzarote, February 2010, submitted

Published
2010
Full Text
View/download PDF

10. The CoRoT target HD 49933: 2- Comparison of theoretical mode amplitudes with observations

Author

Samadi, R., Ludwig, H. -G., Belkacem, K., Goupil, M. J., Benomar, O., Mosser, B., Dupret, M. -A., Baudin, F., Appourchaux, T., and Michel, E.

Subjects
Astrophysics - Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

From the seismic data obtained by CoRoT for the star HD 49933 it is possible, as for the Sun, to constrain models of the excitation of acoustic modes by turbulent convection. We compare a stochastic excitation model described in Paper I (arXiv:0910.4027) with the asteroseismology data for HD 49933, a star that is rather metal poor and significantly hotter than the Sun. Using the mode linewidths measured by CoRoT for HD 49933 and the theoretical mode excitation rates computed in Paper I, we derive the expected surface velocity amplitudes of the acoustic modes detected in HD 49933. Using a calibrated quasi-adiabatic approximation relating the mode amplitudes in intensity to those in velocity, we derive the expected values of the mode amplitude in intensity. Our amplitude calculations are within 1-sigma error bars of the mode surface velocity spectrum derived with the HARPS spectrograph. The same is found with the mode amplitudes in intensity derived for HD 49933 from the CoRoT data. On the other hand, at high frequency, our calculations significantly depart from the CoRoT and HARPS measurements. We show that assuming a solar metal abundance rather than the actual metal abundance of the star would result in a larger discrepancy with the seismic data. Furthermore, calculations that assume the ``new'' solar chemical mixture are in better agreement with the seismic data than those that assume the ``old'' solar chemical mixture. These results validate, in the case of a star significantly hotter than the Sun and Alpha Cen A, the main assumptions in the model of stochastic excitation. However, the discrepancies seen at high frequency highlight some deficiencies of the modelling, whose origin remains to be understood., 8 pages, 3 figures (B-W and color), accepted for publication in Astronomy & Astrophysics. Corrected typo in Eq. (4). Updated references. Language improvements

Published
2009

11. The B0.5IVe CoRoT target HD 49 330. I. Photometric analysis from CoRoT data

Author

Huat, A.L., Hubert, A.M., Floquet, M., Neiner, C., Frémat, Y., Gutiérrez Soto, Juan, Baudin, F., Andrade, L., De Batz, B., Diago Nebot, Pascual David, Emilio, M., Espinosa-Lara, F., Fabregat Llueca, Juan, Janot-Pacheco, E., Leroy, B., Martayan, C., Semaan, T., Suso, J., Michel, E., and Samadi, R.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astronomia, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Ciència Ensenyament
Abstract

Context. Be stars undergo outbursts producing a circumstellar disk from the ejected material. The beating of non-radial pulsations has been put forward as a possible mechanism of ejection. Aims. We analyze the pulsational behavior of the early B0.5IVe star HD 49330 observed during the first CoRoT long run towards the Galactical anticenter (LRA1). This Be star is located close to the lower edge of the β Cephei instability strip in the HR diagram and showed a 0.03 mag outburst during the CoRoT observations. It is thus an ideal case for testing the aforementioned hypothesis. Methods. We analyze the CoRoT light curve of HD 49330 usin g Fourier methods and non-lin ear least square fitting. Results. In this star, we find pulsation modes typical of β Cep stars (p modes) and SPB stars (g modes) with amplitude variations along the run directly correlated with the outburst. These results provide new clues about the origin of the Be phenomenon as well as strong constraints on the seismic modelling of Be stars.

Published
2009

12. Asteroseismic analysis of the CoRoT ��-Scuti star HD174936

Author

Hern��ndez, A. Garc��a, Moya, A., Michel, E., Garrido, R., Su��rez, J. C., Rodr��guez, E., Amado, P. J., Mart��n-Ru��z, S., Rolland, A., Poretti, E., Samadi, R., Baglin, A., Auvergne, M., Catala, C., Lefevre, L., and Baudin, F.

Subjects
Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

We present an analysis of the ��-Scuti star object HD 174936 (ID 7613) observed by CoRoT during the first short run SRc01 (27 days). A total number of 422 frequencies we are extracted from the light curve using standard prewhitening techniques. This number of frequencies was obtained by considering a spectral significance limit of sig = 10 using the software package SigSpec. Our analysis of the oscillation frequency spectrum reveals a spacing periodicity of around 52 \muHz. Although modes considered here are not in the asymptotic regime, a comparison with stellar models confirms that this signature may stem from a quasi-periodic pattern similar to the so-called large separation in solar-like stars., 7 pages, 7 figures, 2 tables. Accepted for publication in A&A CoRoT Special Feature

Published
2009
Full Text
View/download PDF

13. The pulsations of the B5IVe star HD 181 231 observed with CoRoT and ground-based spectroscopy

Author

Neiner, C., Gutiérrez Soto, Juan, Baudin, F., De Batz, B., Frémat, Y., Huat, A.L., Floquet, M., Hubert, A.M., Leroy, B., Diago Nebot, Pascual David, Poretti, E., Carrier, F., Rainer, M., Catala, C., Thizy, O., Buil, C., Ribeiro, J., Andrade, L., Emilio, M., Espinosa-Lara, F., Fabregat Llueca, Juan, Janot-Pacheco, E., Martayan, C., Semaan, T., Suso, J., Baglin, A., Michel, E., and Samadi, R.

Subjects
Astronomia, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Ciència Ensenyament
Abstract

Context. HD 181231 is a B5IVe star, which has been observed with the CoRoT satellite during ∼5 consecutive months and simultaneously from the ground in spectroscopy and spectropolarimetry. Aims. By analysing these data, we aim to detect and characterize as many pulsation frequencies as possible, to search for the presence of beating effects possibly at the origin of the Be phenomenon. Our results will also pr ovide a basis for seismic modelling. Methods. The fundamental parameters of the star are determined from spectral fitting and from the study of the circumstellar emission. The CoRoT photometric data and ground-based spectroscopy are analysed using several Fourier Techniques: CLEAN-NG,PASPER,and TISAFT, as well as a time-frequency technique. A search for a magnetic field is performed by applying the LSD technique to the spectropolarimetric data. Results. We find that HD 181231 is a B5IVe star seen with an inclination of ∼45 degrees. No magnetic field is detected in its photo-sphere. We detect at least 10 independent significant frequencies of variations among the 54 detected frequencies, interpreted in termsof non-radial pulsation modes and rotation. Two longer-term variations are also detected: one at ∼14 days resulting from a beating effect between the two main frequencies of short-term variations, the other at ∼116 days due either to a beating of frequencies or to a zonal pulsation mode. Conclusions. Our analysis of the CoRoT light curve and ground-based spectroscopic data of HD 181231 has led to the determination of the fundamental and pulsational parameters of the star, including beating effects. This will allow a precise seismic modelling of this star.

Published
2009

14. OH and H2O maser variations in W33B

Author

Chiappini, C., Anders, F., Rodrigues, T., Miglio, A., Montalban, J., Mosser, B., Girardi, L., Valentini, M., Noels, A., Morel, T., Minchev, I., Steinmetz, M., Santiago, B., Schultheis, M., Martig, M., da Costa, L., Maia, M., Allende Prieto, C., de Assis Peralta, R., Hekker, S., Themessl, N., Kallinger, T., Garcia, R., Mathur, S., Baudin, F., Beers, T., Cunha, K., Harding, P., Holtzman, J., Majewski, S., Mészáros, Sz., Nidever, D., Pan, K., Schiavon, R., Shetrone, M., Schneider, D., Stassun, K., Colom, P., Lekht, E., Pashchenko, M., Rudnitskij, G., Leibniz-Institut für Astrophysik Potsdam (AIP), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, 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, 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Département d'astrophysique, Géophysique et Océanographie (AGO), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 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, 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), Liverpool John Moores University (LJMU), Laboratoire Géosciences Océan (LGO), Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), School of Physics and Astronomy, University of Birmingham [Birmingham], Institute for Astronomy [Vienna], University of Vienna [Vienna], Institut de Physique du Globe de Paris (IPG Paris), Space Science Institute [Boulder] (SSI), 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), Center for the Study of Cosmic Evolution (CSCE), Michigan State University [East Lansing], Michigan State University System-Michigan State University System, Department of Geography, Department of geography, Université Nice Sophia Antipolis (... - 2019) (UNS), 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 Français de Recherche pour l'Exploitation de la Mer - Brest (IFREMER Centre de Bretagne), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris, 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, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
individual objects, 85A15, lines and bands -ISM, Astrophysics::High Energy Astrophysical Phenomena, Central object, FOS: Physical sciences, Astrophysics, 01 natural sciences, W33B, law.invention, Radio telescope, symbols.namesake, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Maser, masers -ISM, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, magnetic fields -ISM, Line (formation), [PHYS]Physics [physics], Physics, Zeeman effect, 010308 nuclear & particles physics, molecules -ISM, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Magnetic field, Wavelength, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), symbols, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Excitation
Abstract

The active star-forming region W33B is a source of OH and H2O maser emission located in distinct zones around the central object. The aim was to obtain the complete Stokes pattern of polarised OH maser emission, to trace its variability and to investigate flares and long-term variability of the H2O maser and evolution of individual emission features. Observations in the OH lines at a wavelength of 18 cm were carried out on the Nan\c{c}ay radio telescope (France) at a number of epochs in 2008--2014; H2O line observations (long-term monitoring) at a wavelength of 1.35 cm were performed on the 22-metre radio telescope of the Pushchino Radio Astronomy Observatory (Russia) between 1981 and 2014. We have observed strong variability of the emission features in the main 1665- and 1667-MHz OH lines as well as in the 1612-MHz satellite line. Zeeman splitting has been detected in the 1665-MHz OH line at 62 km/s and in the 1667-MHz line at 62 and 64 km/s. The magnetic field intensity was estimated to be from 2 to 3 mG. The H2O emission features form filaments, chains with radial-velocity gradients, or more complicated structures including large-scale ones. Long-term observations of the hydroxyl maser in the W33B region have revealed narrowband polarised emission in the 1612-MHz line with a double-peak profile characteristic of Type IIb circumstellar masers. The 30-year monitoring of the water-vapour maser in W33B showed several strong flares of the H2O line. The observed radial-velocity drift of the H2O emission features suggests propagation of an excitation wave in the masering medium with a gradient of radial velocities. In OH and H2O masers some turbulent motions of material are inferred., Comment: 18 pages, 12 figures

Published
2015

15. solarFLAG hare and hounds: on the extraction of rotational p-mode splittings from seismic, Sun-as-a-star data

Author

Chaplin, W. J., Appourchaux, T., Baudin, F., Boumier, P., Elsworth, Y., Fletcher, S. T., Fossat, E., Garcia, R. A., Isaak, G. R., Jimenez, A., Jimenez-Reyes, S. J., Lazrek, M., Leibacher, J. W., Lochard, J., New, R., Palle, P., Regulo, C., Salabert, D., Seghouani, N., Toutain, T., and Wachter, R.

Subjects
Astrophysics (astro-ph), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics
Abstract

We report on results from the first solar Fitting at Low-Angular degree Group (solar FLAG) hare-and-hounds exercise. The group is concerned with the development of methods for extracting the parameters of low-l solar p mode data (`peak bagging'), collected by Sun-as-a-star observations. Accurate and precise estimation of the fundamental parameters of the p modes is a vital pre-requisite of all subsequent studies. Nine members of the FLAG (the `hounds') fitted an artificial 3456-d dataset. The dataset was made by the `hare' (WJC) to simulate full-disc Doppler velocity observations of the Sun. The rotational frequency splittings of the l=1, 2 and 3 modes were the first parameter estimates chosen for scrutiny. Significant differences were uncovered at l=2 and 3 between the fitted splittings of the hounds. Evidence is presented that suggests this unwanted bias had its origins in several effects. The most important came from the different way in which the hounds modeled the visibility ratio of the different rotationally split components. Our results suggest that accurate modelling of the ratios is vital to avoid the introduction of significant bias in the estimated splittings. This is of importance not only for studies of the Sun, but also of the solar analogues that will targets for asteroseismic campaigns.

Published
2006
Full Text
View/download PDF

16. The life of stars and their planets

Author

Catala, C., Aerts, C., Aigrain, S., Antonello, E., Appourchaux, T., Auvergne, M., Baglin, A., Barge, P., Barstow, M. A., Baudin, F., Boumier, P., Collier Cameron, A., Christensen-Dalsgaard, J., Cutispoto, G., Deeg, H., Deleuil, M., Desidera, S., Donati, J. -F, Favata, F., Foing, B. H., Gameiro, J. F., Garcia, R., Garrido, F., Horne, K., Lanza, A. F., Lanzafame, A. C., Lecavelier Des Etangs, A., Léger, A., Mas-Hesse, M., Sergio Messina, Micela, G., Michel, E., Monteiro, M. J. P. F. G., Mosser, B., Noels, A., Pagano, I., Piotto, G., Poretti, E., Rauer, H., Roca-Cortes, T., Rodono, M., Rouan, D., Roxburgh, I., Schneider, J., Strassmeier, K., Turck-Chièze, S., Vauclair, S., Vidal-Madjar, A., Weiss, W. W., Wheatley, P., 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, 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), Pôle Astronomie du LESIA, 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, 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)-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)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
exoplanets, evolution, Astrophysics::Solar and Stellar Astrophysics, magnetic activity, Astrophysics::Earth and Planetary Astrophysics, structure, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Stars, Astrophysics::Galaxy Astrophysics
Abstract

We lack a reliable scenario for the formation and evolution of stars and their planetary systems, involving key factors such as magnetic fields and turbulence. We present the case for a mission concept that will clarify these problems and give us a global view of the evolution of combined star and planetary systems. This will be achieved by simultaneously addressing the search for planetary transits in front of a large number of stars, including many nearby stars, the study of their internal structure and evolution via asteroseismology, and that of their magnetic activity, via UV monitoring.

17. PLATO as it is: a legacy mission for Galactic archaeology

Author

A. Miglio, C. Chiappini, B. Mosser, G. R. Davies, K. Freeman, L. Girardi, P. Jofré, D. Kawata, B. M. Rendle, M. Valentini, L. Casagrande, W. J. Chaplin, G. Gilmore, K. Hawkins, B. Holl, T. Appourchaux, K. Belkacem, D. Bossini, K. Brogaard, M.‐J. Goupil, J. Montalbán, A. Noels, F. Anders, T. Rodrigues, G. Piotto, D. Pollacco, H. Rauer, C. Allende Prieto, P. P. Avelino, C. Babusiaux, C. Barban, B. Barbuy, S. Basu, F. Baudin, O. Benomar, O. Bienaymé, J. Binney, J. Bland‐Hawthorn, A. Bressan, C. Cacciari, T. L. Campante, S. Cassisi, J. Christensen‐Dalsgaard, F. Combes, O. Creevey, M. S. Cunha, R. S. Jong, P. Laverny, S. Degl'Innocenti, S. Deheuvels, É. Depagne, J. Ridder, P. Di Matteo, M. P. Di Mauro, M.‐A. Dupret, P. Eggenberger, Y. Elsworth, B. Famaey, S. Feltzing, R. A. García, O. Gerhard, B. K. Gibson, L. Gizon, M. Haywood, R. Handberg, U. Heiter, S. Hekker, D. Huber, R. Ibata, D. Katz, S. D. Kawaler, H. Kjeldsen, D. W. Kurtz, N. Lagarde, Y. Lebreton, M. N. Lund, S. R. Majewski, P. Marigo, M. Martig, S. Mathur, I. Minchev, T. Morel, S. Ortolani, M. H. Pinsonneault, B. Plez, P. G. Prada Moroni, D. Pricopi, A. Recio‐Blanco, C. Reylé, A. Robin, I. W. Roxburgh, M. Salaris, B. X. Santiago, R. Schiavon, A. Serenelli, S. Sharma, V. Silva Aguirre, C. Soubiran, M. Steinmetz, D. Stello, K. G. Strassmeier, P. Ventura, R. Ventura, N. A. Walton, C. C. Worley, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, 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, 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), Arizona State University [Tempe] (ASU), Leibniz-Institut für Astrophysik Potsdam (AIP), Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], School of Physics and Astronomy [Birmingham], University of Birmingham [Birmingham], Heckscher-Klinikum, Danish AsteroSeismology Centre (DASC), Universidade Federal de São Paulo (UNIFESP), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Department of Astronomy [New Haven], Yale University [New Haven], Evolution et Modélisation des Bassins Sédimentaires (EMBS), Institut des Sciences de la Terre de Paris (iSTeP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Department of Biomedical, Metabolic and Neural Sciences [Modena], Chaire Galaxies et cosmologie, Collège de France (CdF (institution)), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidade de Aveiro, Joseph Louis LAGRANGE (LAGRANGE), 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), 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), Las Cumbres Observatory (LCO), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Université de Strasbourg (UNISTRA), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universitat de Girona (UdG), Max-Planck-Institut für Extraterrestrische Physik (MPE), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, SETI Institute, University of Illinois at Urbana Champaign (UIUC), University of Illinois at Urbana-Champaign [Urbana], University of Illinois System-University of Illinois System, Universidade Federal de Santa Catarina = Federal University of Santa Catarina [Florianópolis] (UFSC), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), 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), 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), Space Science Institute [Boulder] (SSI), Department of Astronomy (Ohio State University), Ohio State University [Columbus] (OSU), Laboratoire Univers et Particules de Montpellier (LUPM), 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), Astrophysical Research Institute [Liverpool], Liverpool John Moore University (ljmu), Institute of Space Sciences [Barcelona] (ICE-CSIC), Spanish National Research Council [Madrid] (CSIC), Sydney Institute for Astronomy (SIfA), The University of Sydney, M2A 2017, 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)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Leibniz Institute for Astrophysics Potsdam (AIP), Symbiose Marine (SM), Evolution Paris Seine, Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), DNRF106, The Danish National Research Foundation, Centre National d’Etudes Spatiales, PRIN INAF 2014 - CRA 1.05.01.94.05, Science and Technology Facilities Council, Programme National Cosmologie et Galaxies (CNRS/INSU, France), IF/00894/2012/, Federación Española de Enfermedades Raras, CNES Fellowship, 615604, ERC Consolidator (STARKEY), Federaal Wetenschapsbeleid, ESP2015-66134-R, Ministerio de Economía y Competitividad, European Commission's Seventh Framework Programme, Swedish National Space Board, European Commission, DLR, FT1400147, Australian Research Council, NNX16AI09G, National Aeronautics and Space Administration, European Cooperation in Science and Technology, CH1188/2-1, DFG, CA16117, ChETEC COST Action, 10118, Villum Fonden, European Union FP7 program, 320360, ERC, UID/FIS/04434/2013, FCT, G1502, NYUAD Institute, Programme National de Physique Stellaire (PNPS), ITA, USA, GBR, FRA, DEU, ESP, Federal University of Sao Paulo (Unifesp), Université Paris-Saclay, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Collège de France - Chaire Galaxies et cosmologie, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Nice Sophia Antipolis (1965 - 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, 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), 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), Université de Genève = University of Geneva (UNIGE), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, University of Illinois System, 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), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), Miglio A., Chiappini C., Mosser B., Davies G.R., Freeman K., Girardi L., Jofre P., Kawata D., Rendle B.M., Valentini M., Casagrande L., Chaplin W.J., Gilmore G., Hawkins K., Holl B., Appourchaux T., Belkacem K., Bossini D., Brogaard K., Goupil M.-J., Montalban J., Noels A., Anders F., Rodrigues T., Piotto G., Pollacco D., Rauer H., Prieto C.A., Avelino P.P., Babusiaux C., Barban C., Barbuy B., Basu S., Baudin F., Benomar O., Bienayme O., Binney J., Bland-Hawthorn J., Bressan A., Cacciari C., Campante T.L., Cassisi S., Christensen-Dalsgaard J., Combes F., Creevey O., Cunha M.S., Jong R.S., Laverny P., Degl'Innocenti S., Deheuvels S., Depagne E., Ridder J., Matteo P.D., Mauro M.P.D., Dupret M.-A., Eggenberger P., Elsworth Y., Famaey B., Feltzing S., Garcia R.A., Gerhard O., Gibson B.K., Gizon L., Haywood M., Handberg R., Heiter U., Hekker S., Huber D., Ibata R., Katz D., Kawaler S.D., Kjeldsen H., Kurtz D.W., Lagarde N., Lebreton Y., Lund M.N., Majewski S.R., Marigo P., Martig M., Mathur S., Minchev I., Morel T., Ortolani S., Pinsonneault M.H., Plez B., Moroni P.G.P., Pricopi D., Recio-Blanco A., Reyle C., Robin A., Roxburgh I.W., Salaris M., Santiago B.X., Schiavon R., Serenelli A., Sharma S., Aguirre V.S., Soubiran C., Steinmetz M., Stello D., Strassmeier K.G., Ventura P., Ventura R., Walton N.A., Worley C.C., Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), Université Nice Sophia Antipolis (... - 2019) (UNS), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
RED-GIANT STARS, Astrophysics, 01 natural sciences, COROT ASTEROSEISMOLOGY FIELDS, Astrophysics::Solar and Stellar Astrophysics, VELOCITY EXPERIMENT RAVE, Galaxy: structure, 010303 astronomy & astrophysics, SUN-LIKE STAR, QC, QB, Physics, structure - stars: abundances - stars: fundamental parameters - stars: oscillations - surveys [Galaxy], Astrophysics - Solar and Stellar Astrophysics, stars: fundamental parameters, stars: oscillations, Astrophysics::Earth and Planetary Astrophysics, SOLAR-LIKE OSCILLATIONS, THICK DISK, stars: abundances, Relation (database), DATA RELEASE, Milky Way, surveys, Astronomy and Astrophysics, Space and Planetary Science, FOS: Physical sciences, MILKY-WAY DISK, F500, Kepler, Asteroseismology, ATMOSPHERIC PARAMETERS, Settore FIS/05 - Astronomia e Astrofisica, 0103 physical sciences, Quality (philosophy), Galaxy: structure â stars: abundances â stars: fundamental parameters â stars: oscillations â surveys, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 010308 nuclear & particles physics, Galaxy: structure – stars: abundances – stars: fundamental parameters – stars: oscillations – surveys, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Data science, Astrophysics - Astrophysics of Galaxies, Galaxy, COLD DARK-MATTER, Stars, Astrophysics of Galaxies (astro-ph.GA), Stellar physics, Galaxy: structure – stars: abundances – stars: fundamental parameters – stars: oscillations – surveys, Galaxy: structure - stars: abundances - stars: fundamental parameters - stars: oscillations - surveys
Abstract

Deciphering the assembly history of the Milky Way is a formidable task, which becomes possible only if one can produce high-resolution chrono-chemo-kinematical maps of the Galaxy. Data from large-scale astrometric and spectroscopic surveys will soon provide us with a well-defined view of the current chemo-kinematical structure of the Milky Way, but will only enable a blurred view on the temporal sequence that led to the present-day Galaxy. As demonstrated by the (ongoing) exploitation of data from the pioneering photometric missions CoRoT, Kepler, and K2, asteroseismology provides the way forward: solar-like oscillating giants are excellent evolutionary clocks thanks to the availability of seismic constraints on their mass and to the tight age-initial-mass relation they adhere to. In this paper we identify five key outstanding questions relating to the formation and evolution of the Milky Way that will need precise and accurate ages for large samples of stars to be addressed, and we identify the requirements in terms of number of targets and the precision on the stellar properties that are needed to tackle such questions. By quantifying the asteroseismic yields expected from PLATO for red-giant stars, we demonstrate that these requirements are within the capabilities of the current instrument design, provided that observations are sufficiently long to identify the evolutionary state and allow robust and precise determination of acoustic-mode frequencies. This will allow us to harvest data of sufficient quality to reach a 10% precision in age. This is a fundamental pre-requisite to then reach the more ambitious goal of a similar level of accuracy, which will only be possible if we have to hand a careful appraisal of systematic uncertainties on age deriving from our limited understanding of stellar physics, a goal which conveniently falls within the main aims of PLATO's core science., 17 pages, 9 figures, accepted for publication in Astronomical Notes

Published
2017

Catalog

Books, media, physical & digital resources
See catalog results