Author: "Catala, C." / Database: OpenAIRE - Searchworks@Jio Institute Digital Library Search Results

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1. 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, Baudin, F, Boumier, P, Cameron, A, Christensen-Dalsgaard, J, Cutispoto, G, Deeg, H, Deleuil, M, Desidera, S, Donati, J, Favata, F, Foing, B, Gameiro, J, García, R, Garrido, R, Horne, K, and Lanza, A
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.
Published: 2016

2. Instability domains of delta Scuti and Slowly Pulsating B stars : How will the CoRoT satellite help to determine the limits ?

Author: Lefèvre, L., Michel, E., Aerts, C.C., Kaiser, A., Neiner, C., Poretti, E., Garrido, R., Baglin, A., Auvergne, M., Catala, C., Weiss, W., Balaguer-Nunez, L., Maceroni, C., Ribas, I., 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, and Ingénieurs, Techniciens et Administratifs
Subjects: Astronomy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract: Contains fulltext : 76072.pdf (Publisher’s version ) (Open Access) 5 p.
Published: 2009

3. 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 - 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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 - 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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

4. 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

5. CoRoT Observations of O Stars: Diverse Origins of Variability

Author: Blomme, R., Briquet, M., Degroote, P., Mahy, L., Aerts, Conny, 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., Rauw, G., Schiller, F., Simon-Diaz, S., Smolders, K., Ventura, P., Vučković, M., Auvergne, M., Baglin, A., Baudin, F., Catala, C., Michel, E., Samadi, R., Rubert, C., St-Louis, N., Moffat, A.F.J., Drissen, L., and Drissen, L.
Subjects: Astronomy, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Astronomical Society of the Pacific Conference Series
Abstract: Contains fulltext : 111302.pdf (Author’s version preprint ) (Open Access) Contains fulltext : 111302.pdf (Publisher’s version ) (Closed access)
Published: 2013

6. 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
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7. 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., Rauw, G., Schiller, F., Simon-Diaz, S., Smolders, K., Ventura, P., Vučković, M., Auvergne, M., Baglin, A., Baudin, F., Catala, C., Michel, E., Samadi, R., Blomme, Briquet, Degroote, Mahy, Aerts, Cuypers, Godart, Gosset, Hareter, Montalban, Morel, Nieva, M. F., Noels, Oreiro, Poretti, Przybilla, Rainer, Rauw, Schiller, Simon-Diaz, Smolders, Ventura, Vučković, Auvergne, Baglin, Baudin, Catala, Michel, and Samadi
Published: 2012

8. The stellar wind cycles and planetary radio emission of the t Boo system

Author: Vidotto, Aline, Fares, Rim, Jardine, Moira Mary, Donati, J.-F., Opher, M., Moutou, C., Catala, C., Gombosi, T. I., Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-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), University of St Andrews [Scotland], Department of Astronomy [Boston], Boston University [Boston] (BU), Laboratoire d'Astrophysique de Marseille (LAM), 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), 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), University of Michigan [Ann Arbor], University of Michigan System, Université de Genève = University of Geneva (UNIGE), 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), 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), Science & Technology Facilities Council, and University of St Andrews. School of Physics and Astronomy
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], MHD, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, planetary systems [Radio continuum], magnetic field [Stars], individual: Tau Bootis [Stars], Astrophysics - Solar and Stellar Astrophysics, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, winds, outflows [Stars], Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Numerical [Methods], QB, Astrophysics - Earth and Planetary Astrophysics
Abstract: Tau Boo is an intriguing planet-host star that is believed to undergo magnetic cycles similar to the Sun, but with a duration that is about one order of magnitude smaller than that of the solar cycle. With the use of observationally derived surface magnetic field maps, we simulate the magnetic stellar wind of Tau Boo by means of three-dimensional MHD numerical simulations. As the properties of the stellar wind depend on the particular characteristics of the stellar magnetic field, we show that the wind varies during the observed epochs of the cycle. Although the mass loss-rates we find (~2.7e-12 Msun/yr) vary less than 3 per cent during the observed epochs of the cycle, our derived angular momentum loss-rates vary from 1.1 to 2.2e32erg. The spin-down times associated to magnetic braking range between 39 and 78Gyr. We also compute the emission measure from the (quiescent) closed corona and show that it remains approximately constant through these epochs at a value of ~10^{50.6} cm^{-3}. This suggests that a magnetic cycle of Tau Boo may not be detected by X-ray observations. We further investigate the interaction between the stellar wind and the planet by estimating radio emission from the hot-Jupiter that orbits at 0.0462 au from Tau Boo. By adopting reasonable hypotheses, we show that, for a planet with a magnetic field similar to Jupiter (~14G at the pole), the radio flux is estimated to be about 0.5-1 mJy, occurring at a frequency of 34MHz. If the planet is less magnetised (field strengths roughly, 15 pages, 10 figures, MNRAS accepted
Published: 2012

9. Accurate fundamental parameters and detailed abundance patterns from spectroscopy of 93 solar-type Kepler targets

Author: Bruntt, H., Basu, S., Smalley, B., Chaplin, W. J., Verner, G. A., Bedding, T. R., Catala, C., Gazzano, J. -C., Molenda-Zakowicz, J., Thygesen, A. O., Uytterhoeven, K., Hekker, S., Huber, D., Karoff, C., Mathur, S., Mosser, B., Appourchaux, T., Campante, T. L., Elsworth, Y., Garcia, R. A., Handberg, R., Metcalfe, T. S., Quirion, P. -O., Regulo, C., Roxburgh, I. W., Stello, D., Christensen-Dalsgaard, J., Kawaler, S. D., Kjeldsen, H., Morris, R. L., Quintana, E. V., Sanderfer, D. T., 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), and Low Energy Astrophysics (API, FNWI)
Subjects: [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]
Abstract: International audience; We present a detailed spectroscopic study of 93 solar-type stars that are targets of the NASA/Kepler mission and provide detailed chemical composition of each target. We find that the overall metallicity is well represented by Fe lines. Relative abundances of light elements (CNO) and a elements are generally higher for low-metallicity stars. Our spectroscopic analysis benefits from the accurately measured surface gravity from the asteroseismic analysis of the Kepler light curves. The accuracy on the log g parameter is better than 0.03 dex and is held fixed in the analysis. We compare our Teff determination with a recent colour calibration of VT-KS [TYCHO V magnitude minus Two Micron All Sky Survey (2MASS) KS magnitude] and find very good agreement and a scatter of only 80 K, showing that for other nearby Kepler targets, this index can be used. The asteroseismic log g values agree very well with the classical determination using Fe iFe ii balance, although we find a small systematic offset of 0.08 dex (asteroseismic log g values are lower). The abundance patterns of metals, a elements and the light elements (CNO) show that a simple scaling by [Fe/H] is adequate to represent the metallicity of the stars, except for the stars with metallicity below -0.3, where a-enhancement becomes important. However, this is only important for a very small fraction of the Kepler sample. We therefore recommend that a simple scaling with [Fe/H] be employed in the asteroseismic analyses of large ensembles of solar-type stars.
Published: 2012

10. PLATO – The Next Generation Exoplanet Finder

Author: Dreyer, C, Rauer, H, PLATO, consortium, and Catala, C
Subjects: exoplanets, transit detection, asteroseismology, PLATO
Published: 2012

11. Accurate parameters of 93 solar-type Kepler targets

Author: Bruntt, H., Basu, S., Smalley, B., Chaplin, W. J., Verner, G. A., Bedding, T. R., Catala, C., Gazzano, J. -C., Molenda-Zakowicz, J., Thygesen, A. O., Uytterhoeven, K., Hekker, S., Huber, D., Karoff, C., Mathur, S., Mosser, B., Appourchaux, T., Campante, T. L., Elsworth, Y., Garcia, R. A., Handberg, R., Metcalfe, T. S., Quirion, P. -O., Regulo, C., Roxburgh, I. W., Stello, D., Christensen-Dalsgaard, J., Kawaler, S. D., Kjeldsen, H., Morris, R. L., Quintana, E. V., and Sanderfer, D. T.
Subjects: Astrophysics - Solar and Stellar Astrophysics, FOS: Physical sciences, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: We present a detailed spectroscopic study of 93 solar-type stars that are targets of the NASA/Kepler mission and provide detailed chemical composition of each target. We find that the overall metallicity is well-represented by Fe lines. Relative abundances of light elements (CNO) and alpha-elements are generally higher for low-metallicity stars. Our spectroscopic analysis benefits from the accurately measured surface gravity from the asteroseismic analysis of the Kepler light curves. The log g parameter is known to better than 0.03 dex and is held fixed in the analysis. We compare our Teff determination with a recent colour calibration of V-K (TYCHO V magnitude minus 2MASS Ks magnitude) and find very good agreement and a scatter of only 80 K, showing that for other nearby Kepler targets this index can be used. The asteroseismic log g values agree very well with the classical determination using Fe1-Fe2 balance, although we find a small systematic offset of 0.08 dex (asteroseismic log g values are lower). The abundance patterns of metals, alpha elements, and the light elements (CNO) show that a simple scaling by [Fe/H] is adequate to represent the metallicity of the stars, except for the stars with metallicity below -0.3, where alpha-enhancement becomes important. However, this is only important for a very small fraction of the Kepler sample. We therefore recommend that a simple scaling with [Fe/H] be employed in the asteroseismic analyses of large ensembles of solar-type stars., Comment: MNRAS, in press, 12 pages
Published: 2012
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12. PLATO-The Next Generation Planet Finder

Author: Rauer, H, Catala, C, and PLATO , Consortium
Subjects: transit method, exoplanet, PLATO
Published: 2012

13. CoRoT's view on variable B8/9 stars: spots versus pulsations. Evidence for differential rotation in HD 174648

Author: Degroote, P., Acke, B., Samadi, R., Aerts, C., Kurtz, D. W., Noels, A., Miglio, A., Montalbxe1n, J., Bloemen, S., Baglin, A., Baudin, F., Catala, C., Michel, E., Auvergne, M., Degroote, Acke, Samadi, Aerts, Kurtz, D. W., Noels, Miglio, Montalbxe1n, Bloemen, Baglin, Baudin, Catala, Michel, and Auvergne
Published: 2011

14. Variability in the CoRoT photometry of three hot O-type stars. HD 46223, HD 46150, and HD 46966

Author: Blomme, R., Mahy, L., Catala, C., Cuypers, J., Gosset, E., Godart, M., Montalban, J., Ventura, P., Rauw, G., Morel, T., Degroote, P., Aerts, C., Noels, A., Michel, E., Baudin, F., Baglin, A., Auvergne, M., Samadi, R., Blomme, Mahy, Catala, Cuypers, Gosset, Godart, Montalban, Ventura, Rauw, Morel, Degroote, Aerts, Noels, Michel, Baudin, Baglin, Auvergne, and Samadi
Published: 2011

15. CoRoT\,102699796, the first metal-poor Herbig Ae pulsator: a hybrid $\delta$ Sct-$\gamma$ Dor variable?

Author: Ripepi, V, Cusano, F, Di Criscienzo, M, Catanzaro, Giovanni, Palla, F, Marconi, M, Ventura, P, Neiner, C, Catala, C, Bernabei, S., INAF-Osservatorio Astronomico di Capodimonte (INAF-OAC), INAF-Osservatorio Astronomico di Roma (INAF-OAR), INAF-Osservatorio Astrofisico di Catania (INAF-OACt), INAF-Osservatorio Astrofisico di Arcetri (INAF-OAA), 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), Etoile, 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, 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), and INAF-Osservatorio Astronomico di Bologna (OABO)
Subjects: Astrophysics - Solar and Stellar Astrophysics, Physics - Data Analysis, Statistics and Probability, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract: We present the analysis of the time series observations of CoRoT\,102699796 obtained by the CoRoT satellite that show the presence of five independent oscillation frequencies in the range 3.6-5 c/d. Using spectra acquired with FLAMES@VLT, we derive the following stellar parameters: spectral type F1V, T$_{\rm eff}$=7000$\pm$200 K, log(g)=$3.8\pm0.4$, [M/H]=$-1.1\pm0.2$, $v$sin$i$=$50\pm5$ km/s, L/L$_{\odot}$=21$^{+21}_{-11}$. Thus, for the first time we report the existence of a metal poor, intermediate-mass PMS pulsating star. Ground-based and satellite data are used to derive the spectral energy distribution of CoRoT\,102699796 extending from the optical to mid-infrared wavelengths. The SED shows a significant IR excess at wavelengths greater than $\sim5 \mu$. We conclude that CoRoT\,102699796 is a young Herbig Ae (F1Ve) star with a transitional disk, likely associated to the HII region [FT96]213.1-2.2. The pulsation frequencies have been interpreted in the light of the non-radial pulsation theory, using the LOSC code in conjunction with static and rotational evolutionary tracks. A minimization algorithm was used to find the best-fit model with M=1.84 M$_{\odot}$, T$_{\rm eff}$=6900 K which imply an isochronal age of t$\sim$2.5 Myr. This result is based on the interpretation of the detected frequencies as $g$-modes of low-moderate $n$-value. To our knowledge, this is the first time that such modes are identified in a intermediate-mass PMS pulsating star. Since CoRoT\,102699796 lies in the region of the HR diagram where the $\delta$ Sct and $\gamma$ Dor instability strips intersect, we argue that the observed pulsation characteristics are intermediate between these classes of variables, i.e. CoRoT\,102699796 is likely the first PMS hybrid $\gamma$ Dor-$\delta$ Sct pulsator ever studied., Comment: 13 pages, 7 figures. Accepted for publication in Monthly Notices of the RAS
Published: 2011

16. CoRoT\,102699796, the first metal-poor Herbig Ae pulsator: a hybrid $��$ Sct-$��$ Dor variable?

Author: Ripepi, V., Cusano, F., Di Criscienzo, M., Catanzaro, G., Palla, F., Marconi, M., Ventura, P., Neiner, C., Catala, C., and Bernabei, S.
Subjects: 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), Data Analysis, Statistics and Probability (physics.data-an)
Abstract: We present the analysis of the time series observations of CoRoT\,102699796 obtained by the CoRoT satellite that show the presence of five independent oscillation frequencies in the range 3.6-5 c/d. Using spectra acquired with FLAMES@VLT, we derive the following stellar parameters: spectral type F1V, T$_{\rm eff}$=7000$\pm$200 K, log(g)=$3.8\pm0.4$, [M/H]=$-1.1\pm0.2$, $v$sin$i$=$50\pm5$ km/s, L/L$_{\odot}$=21$^{+21}_{-11}$. Thus, for the first time we report the existence of a metal poor, intermediate-mass PMS pulsating star. Ground-based and satellite data are used to derive the spectral energy distribution of CoRoT\,102699796 extending from the optical to mid-infrared wavelengths. The SED shows a significant IR excess at wavelengths greater than $\sim5 ��$. We conclude that CoRoT\,102699796 is a young Herbig Ae (F1Ve) star with a transitional disk, likely associated to the HII region [FT96]213.1-2.2. The pulsation frequencies have been interpreted in the light of the non-radial pulsation theory, using the LOSC code in conjunction with static and rotational evolutionary tracks. A minimization algorithm was used to find the best-fit model with M=1.84 M$_{\odot}$, T$_{\rm eff}$=6900 K which imply an isochronal age of t$\sim$2.5 Myr. This result is based on the interpretation of the detected frequencies as $g$-modes of low-moderate $n$-value. To our knowledge, this is the first time that such modes are identified in a intermediate-mass PMS pulsating star. Since CoRoT\,102699796 lies in the region of the HR diagram where the $��$ Sct and $��$ Dor instability strips intersect, we argue that the observed pulsation characteristics are intermediate between these classes of variables, i.e. CoRoT\,102699796 is likely the first PMS hybrid $��$ Dor-$��$ Sct pulsator ever studied., 13 pages, 7 figures. Accepted for publication in Monthly Notices of the RAS
Published: 2011
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17. 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
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18. The PLATO End-to-End CCD Simulator -- Modelling space-based ultra-high precision CCD photometry for the assessment study of the PLATO Mission

Author: Zima, W., Arentoft, T., De Ridder, J., Salmon, S., Catala, C., Kjeldsen, H., and Aerts, C.
Subjects: Astrophysics - Solar and Stellar Astrophysics, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: The PLATO satellite mission project is a next generation ESA Cosmic Vision satellite project dedicated to the detection of exo-planets and to asteroseismology of their host-stars using ultra-high precision photometry. The main goal of the PLATO mission is to provide a full statistical analysis of exo-planetary systems around stars that are bright and close enough for detailed follow-up studies. Many aspects concerning the design trade-off of a space-based instrument and its performance can best be tackled through realistic simulations of the expected observations. The complex interplay of various noise sources in the course of the observations made such simulations an indispensable part of the assessment study of the PLATO Payload Consortium. We created an end-to-end CCD simulation software-tool, dubbed PLATOSim, which simulates photometric time-series of CCD images by including realistic models of the CCD and its electronics, the telescope optics, the stellar field, the pointing uncertainty of the satellite (or Attitude Control System [ACS] jitter), and all important natural noise sources. The main questions that were addressed with this simulator were the noise properties of different photometric algorithms, the selection of the optical design, the allowable jitter amplitude, and the expected noise budget of light-curves as a function of the stellar magnitude for different parameter conditions. The results of our simulations showed that the proposed multi-telescope concept of PLATO can fulfil the defined scientific goal of measuring more than 20000 cool dwarfs brighter than mV =11 with a precision better than 27 ppm/h which is essential for the study of earth-like exo-planetary systems using the transit method., 5 pages, submitted for the Proceedings of the 4th HELAS International Conference: Seismological Challenges for Stellar Structure
Published: 2010

19. CoRoT observations of the young open cluster Dolidze 25 RID B-4715-2008

Author: Ripepi, V, Leccia, S, Baglin, A, Ruoppo, A, Bernabei, S, Zwintz, K, Cusano, F, Gandolfi, D, Guenter, Ew, Alencar, S, Marconi, M, Monteiro, Mjpfg, Palla, F, Alcala, Jm, Boehm, T, Catala, C, Chavero, C, Corradi, Ws, Degl'Innocenti, Scilla, de la Reza, R, Deluil, M, Favata, F, Fernandez, M, Gregorio Hetem, J, Lepine, Jdr, Pinheiro, Fjg, PRADA MORONI, PIER GIORGIO, Quast, G, Torres, Cao, and Weiss, W.
Published: 2010

20. PLATO: PLAnetary Transits and Oscillations of stars – the exoplanetary system explorer

Author: Catala, C., Arentoft, T., Fridlund, M., Lindberg, R., Mas-Hesse, J. M., Giuseppina Micela, Pollacco, D., Poretti, E., Rauer, H., Roxburgh, I., Stankov, A., and Udry, S.
Subjects: Transitmethode, Extrsolare Planeten, PLATO
Published: 2010

21. PLATO: detailed design of the telescope optical units

Author: Magrin D., Munari M., Pagano I., Piazza D., Ragazzoni R., Arcidiacono C., Basso S., Dima M., Farinato J., Gambicorti L., Gentile G., Ghigo M., Pace E., Piotto G., Scuderi S., Viotto V., Zima W., and Catala C.
Subjects: Space telescope, Astrophysics::Instrumentation and Methods for Astrophysics, extra-solar planetary system, Astrophysics::Earth and Planetary Astrophysics, wide field camera
Abstract: The project PLAnetary Transits and Oscillations of stars (PLATO) is one of the three medium class (M class) missions selected in 2010 for definition study in the framework of the ESA Cosmic Vision 2015-2025 program. The main scientific goals of PLATO are the i) discovery and study of extra-solar planetary systems, (including those hosting Earthlike planets in their habitable zone) by means of planetary transits detection from space and radial velocity follow-up from ground, and ii) the characterization of the hosting stars through seismic analysis, in order to determine with high accuracy planetary masses and ages. According to the study made by the PLATO Payload Consortium (PPLC) during the PLATO assessment phase, the scientific payload consists of 34 all refractive telescopes having small aperture (120 mm) and wide field of view (greater than 1000 degree2) observing over 0.5-1 micron wavelength band. The telescopes are mounted on a common optical bench and are divided in four families with an overlapping line-of-sight in order to maximize the science return. In this paper, we will describe the detailed design of the Telescope Optical Units (TOUs) focusing on the selected optical configuration and the expected performances.
Published: 2010

22. Evidence for nonlinear resonant mode coupling in the \u03b2 Cephei star HD 180642 (V1449 Aquilae) from CoRoT photometry

Author: Degroote, P., Briquet, M., Catala, C., Uytterhoeven, K., Lefever, K., Morel, T., Aerts, C., Carrier, F., Auvergne, M., Baglin, A., Michel, E., Degroote, Briquet, Catala, Uytterhoeven, Lefever, Morel, Aerts, Carrier, Auvergne, Baglin, and Michel
Published: 2009

23. The asteroseismic ground-based observational counterpart of CoRoT

Author: Uytterhoeven, K., Poretti, E., Mathias, P., Amado, P. J., Rainer, M., Martin-Ruiz, S., Rodriguez, E., Paparo, M., Pollard, K., Maceroni, C., Balaguer-Nunoz, L., Ribas, I., Catala, C., Neiner, C., Garcia, R. A., Group, the CoRoT/SWG Ground-based Observations Working, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), INAF-Osservatorio Astronomico di Brera (INAF-OAB), Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées (LATT), 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), Instituto de Astrofisica de Andalucia, CSIC (IAA), Konkoly Observatory, Research Center for Astronomy and Earth Sciences, University of Canterbury [Christchurch], INAF-Osservatorio Astronomico di Roma (INAF-OAR), DAM. Universitat de Barcelona, Diagonal 647, 08028, Barcelona, Spain, Institut d'Estudis Espacials de Catalunya (IEEC), Edif. Nexus, C/Gran Capità, 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), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Physique stellaire et galactique, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-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), Guzik, Joyce Ann, Bradley, and Paul A.
Subjects: Physics, Astrophysics - Solar and Stellar Astrophysics, Physics::Space Physics, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Observational study, Satellite, Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: We present different aspects of the ground-based observational counterpart of the CoRoT satellite mission. We give an overview of the selected asteroseismic targets, the numerous instruments and observatories involved, and the first scientific results., 3 pages, 2 tables, 1 figure, to be published in the conference proceedings 'Stellar Pulsation: Challenges for Theory and Observation' (31 May - 5 June, Santa Fe, New Mexico, US), publishers: American Institute of Physics
Published: 2009

24. Instability domains of \u03b4 Scuti and Slowly Pulsating B stars : How will the CoRoT satellite help to determine the limits ?

Author: Lefxe8vre, L., Michel, E., Aerts, C., Kaiser, A., Neiner, C., Poretti, E., Garrido, R., Baglin, A., Auvergne, M., Catala, C., Weiss, W., Balaguer-Nxfaxf1ez, L., Maceroni, C., Ribas, I., Lefxe8vre, Michel, Aerts, Kaiser, Neiner, Poretti, Garrido, Baglin, Auvergne, Catala, Weiss, Balaguer-Nxfaxf1ez, Maceroni, and Ribas
Published: 2009

25. Space observations of B stars with CoRoT

Author: Degroote, P., Miglio, A., Debosscher, J., Montalbxe1n, J., Cuypers, J., Briquet, M., De Cat, P., Thoul, A., Morel, T., Niemczura, E., Balaguer-Nxfaxf1ez, L., Maceroni, C., Ribas, I., Noels, A., Aerts, C., Auvergne, M., Baglin, A., Catala, C., Deleuil, M., Michel, E., Ollivier, M., Jorda, L., Samadi, R., Degroote, Miglio, Debosscher, Montalbxe1n, Cuypers, Briquet, De Cat, Thoul, Morel, Niemczura, Balaguer-Nxfaxf1ez, Maceroni, Ribas, Noels, Aerts, Auvergne, Baglin, Catala, Deleuil, Michel, Ollivier, Jorda, and Samadi
Published: 2009

26. HD 50844: the new look of Delta Sct stars from CoRoT space photometry

Author: Poretti, E., Michel, E., Garrido, R., Lefevre, L., Mantegazza, L., Rainer, M., Rodriguez, E., Uytterhoeven, K., Pedro José Amado, Martin-Ruiz, S., Moya, A., Niemczura, E., Suarez, J. C., Zima, W., Baglin, A., Auvergne, M., Baudin, F., Catala, C., Samadi, R., Alvarez, M., Mathias, P., Paparo, M., Papics, P., and Plachy, E.
Subjects: Astrophysics - Solar and Stellar Astrophysics, FOS: Physical sciences, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: It has also been suggested that the detection of a wealth of very low amplitude modes in Delta Sct stars was only a matter of signal--to--noise ratio. Access to this treasure, impossible from the ground, is one of the scientific aims of the space mission CoRoT, a space mission developed and operated by CNES. This work presents the results obtained on HD 50844: the 140,016 datapoints were analysed using independent approaches and several checks performed. A level of 10^{-5} mag was reached in the amplitude spectra of the CoRoT timeseries. The frequency analysis of the CoRoT timeseries revealed hundreds of terms in the frequency range 0--30 d^{-1}. All the cross--checks confirmed this new result. The initial guess that Delta Sct stars have a very rich frequency content is confirmed. The spectroscopic mode identification gives theoretical support since very high--degree modes (up to ell=14) are identified. We also prove that cancellation effects are not sufficient in removing the flux variations associated to these modes at the noise level of the CoRoT measurements. The ground--based observations indicate that HD 50844 is an evolved star that is slightly underabundant in heavy elements, located on the Terminal Age Main Sequence. Probably due to this unfavourable evolutionary status, no clear regular distribution is observed in the frequency set. The predominant term (f_1=6.92 d^{-1}) has been identified as the fundamental radial mode combining ground-based photometric and spectroscopic data. This work is also based on observations made with ESO telescopes under the ESO Large Programme LP178.D-0361 and on data collected at the Observatorio de Sierra Nevada, at the Observatorio Astronomico Nacional San Pedro Martir, and at the Piszkesteto Mountain Station of Konkoly Observatory., 10 pages, 11 figures. Accepted for publication in Astronomy & Astrophysics
Published: 2009

27. Session1A: DATA − Ground-based observations. Veröffentlichungen der Kommission für Astronomie|Communications in Asteroseismology|Communications in Asteroseismology 157 157

Author: Udalski, A., Pamyatnykh, A.A., Aerts, C., Catala, C., Carrier, F., Soszynski, I., Kolenberg, K., Breger, M., Briquet, M., Szymanski, M.K., Lenz, P., Kepler, S. O., Dreizler, S., Schuh, S., Tsantilas, S., Böhm, T., Heber, U., Dimitrov, W., and Zima, W.
Subjects: Mathematics, Physics and Space Research
Published: 2009

28. Blue Dots Team Transits Working Group Review

Author: Alessandro Sozzetti, Afonso, C., Alonso, R., Blank, D. L., Catala, C., Deeg, H., Grenfell, J. L., Hellier, C., Latham, D. W., Minniti, D., Pont, F., and Rauer, H.
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Extrasolare Planeten, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Transit, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Transiting planet systems offer an unique opportunity to observationally constrain proposed models of the interiors (radius, composition) and atmospheres (chemistry, dynamics) of extrasolar planets. The spectacular successes of ground-based transit surveys (more than 60 transiting systems known to-date) and the host of multi-wavelength, spectro-photometric follow-up studies, carried out in particular by HST and Spitzer, have paved the way to the next generation of transit search projects, which are currently ongoing (CoRoT, Kepler), or planned. The possibility of detecting and characterizing transiting Earth-sized planets in the habitable zone of their parent stars appears tantalizingly close. In this contribution we briefly review the power of the transit technique for characterization of extrasolar planets, summarize the state of the art of both ground-based and space-borne transit search programs, and illustrate how the science of planetary transits fits within the Blue Dots perspective., Comment: 9 pages, 3 figures, to be published in the proceedings (ASP Conf. Ser.) of the "Pathways Towards Habitable Planets" conference, held in Barcelona (14-18 Sep 2009)
Published: 2009
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29. 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
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30. Rate and nature of false positives in the CoRoT exoplanet search

Author: Almenara, J, Deeg, H, Aigrain, S, Alonso, R, Auvergne, M, Baglin, A, Barbieri, M, Barge, P, Bordé, P, Bouchy, F, Bruntt, H, Cabrera, Juan, Carone, L, Carpano, S, Catala, C, Csizmadia, Szilard, de la Reza, R, Deleuil, M, Dvorak, R, Erikson, Anders, Fridlund, M, Gandolfi, D, Gillon, M, Gondoin, P, Günther, E, Guillot, T, Hatzes, A, Hébrard, G, Jorda, L, Lammer, H, Léger, A, Llebaria, A, Loiellet, B, Magain, P, Mayor, M, Mazeh, T, Moutou, C, Ofir, A, Ollivier, M, Pätzold, M, Pont, F, Queloz, D, Rauer, Heike, Régulo, C, Renner, Stefan, Rouan, D, Samuel, B, Schneider, J, Shporer, A, Wuchterl, G, Zucker, S, Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), 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, and 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)
Subjects: photometry, FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, Planet, 0103 physical sciences, False positive paradox, false positives, Transit (astronomy), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Galactic plane, Exoplanet, CoRoT, Stars, planetary candidates, exoplanets, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, transit method, False positive rate, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. The CoRoT satellite searches for planets by applying the transit method, monitoring up to 12 000 stars in the galactic plane for 150 days in each observation run. This search is contaminated by a large fraction of false positives, caused by different binary configurations that might be confused with a transiting planet. Aims. We evaluate the rates and nature of false positives in the CoRoT exoplanets search and compare our results with semiempirical predictions. Methods. We consider the detected binary and planet candidates in the first three extended CoRoT runs, and classify the results of the follow-up observations completed to verify their planetary nature. We group the follow-up results into undiluted binaries, diluted binaries, and planets and compare their abundances with predictions from the literature. Results. 83% of the initial detections are classified as false positives using only the CoRoT light-curves, the remaining 17% require follow-up observations. Finally, 12% of the follow-up candidates are planets. The shape of the overall distribution of the false positive rate follows previous predictions, except for candidates with transit depths below about 0.4%. For candidates with transit depths in the range from 0.1 - 0.4%, CoRoT detections are nearly complete, and this difference from predictions is probably real and dominated by a lower than expected abundance of diluted eclipsing binaries., accepted for A&A special issue on CoRoT
Published: 2009

31. Magnetism of Herbig Ae/Be stars

Author: Wade, G. A., Alecian, E., Grunhut, J., Catala, C., Bagnulo, S., Folsom, C. P., and Landstreet, J. D.
Subjects: Astrophysics - Solar and Stellar Astrophysics, 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: Observations of magnetic fields of stars at the pre-main sequence phase can provide important new insights into the complex physics of the late stages of star formation. This is especially true at intermediate stellar masses, where magnetic fields are strong and globally organised, and therefore most amenable to direct study. Recent circularly-polarised spectroscopic observations of pre-main sequence Herbig Ae/Be stars have revealed the presence of organised magnetic fields in the photospheres of a small fraction of these objects. To date, 9 magnetic HAeBe stars have been detected, and those detections confirmed by repeated observations. The morphology and variability of their Stokes V signatures indicates that their magnetic fields have important dipole components of kG strength, and that the dipole is stable on timescales ofat least years. These magnetic stars exhibit a large range of stellar mass, from about 2-13 solar masses, and diverse rotational properties, with vsini from a few km/s to 200 km/s. Most magnetic HAeBe stars show approximately solar abundances; they clearly do not generally exhibit the strong and systematic peculiarities of the magnetic main sequence A and B type stars (the Ap/Bp stars). The observed fractional bulk incidence of magnetic HAeBe stars is about 7%, a value compatible with the incidence of magnetic intermediate-mass stars on the main sequence. This low incidence is at odds with formation scenarios generally involving magnetically-mediated accretion. The similarily between the magnetic properties of the pre-main sequence and main sequence intermediate-mass stars appears compatible with the hypothesis of a fossil origin of magnetism in these objects., Comment: 13 pages, 7 figs, proceedings of "Astronomical Polarimetry 2008: From small to large telescopes" (invited presentation)
Published: 2009
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32. The B0.5IVe CoRoT target HD 49 330. II. Spectroscopic ground-based observations

Author: Floquet, M., Hubert, A.M., Huat, A.L., Frémat, Y., Janot-Pacheco, E., Gutiérrez Soto, Juan, Neiner, C., De Batz, B., Leroy, B., Poretti, E., Amado, P., Catala, C., Rainer, M., Díaz, D., Uytterhoeven, K., Andrade, L., Diago Nebot, Pascual David, M. Emilio, Espinosa-Lara, F., Fabregat Llueca, Juan, Martayan, C., Semaan, T., and Suso, J.
Subjects: Astronomia, Ciència Ensenyament
Abstract: Context. We present spectroscopic ground-based observations of the early Be star HD 49330 obtained simultaneously with the CoRoT-LRA1 run just before the burst observed in the CoRoT data. Aims. Ground-based spectroscopic observations of the early Be star HD 49330 obtained during the precursor phase and just before the start of an outburst allow us to disantangle stellar and circumstellar contributions and identify modes of stellar pulsations in this rapidly rotating star. Methods. Time series analysis (TSA) is performed on photospheric line profiles of He i and Si iii by means of the least squares method. Results. We find two main frequencies f1 = 11.86 c d^−1 and f2 = 16.89 c d^−1 which can be associated with high order p-mode pulsations. We also detect a frequency f3 = 1.51 c d^−1 which can be associated with a low order g-mode. Moreover we show that the stellar line profile variability changed over the spectroscopic run. These results are in agreement with the results of the CoRoT data analysis, as shown in Huat et al. (2009). Conclusions. Our study of mid- and short-term spect roscopic variability allows the identification of p- and g- modes in HD 49330. It also allows us to display changes in the line profile variability before the start of an outburst. This brings new constraints for the seimic modelling of this star.
Published: 2009

33. 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

34. Evidence for nonlinear resonant mode coupling in the β Cephei star HD 180642 (V1449 Aquilae) from CoRoT photometry

Author: Degroote, P., Briquet, M., Catala, C., Uytterhoeven, K., Lefever, K., Morel, T., Aerts, C.C., Carrier, F., Auvergne, M., Baglin, A., and Michel, E.
Subjects: Astronomy, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract: Contains fulltext : 75637.pdf (Publisher’s version ) (Open Access) 13 p.
Published: 2009

35. Low-amplitude variations detected by CoRoT in the B8IIIe star HD 175 869

Author: Gutiérrez Soto, Juan, Floquet, M., Samadi, R., Neiner, C., Garrido, R., Fabregat Llueca, Juan, Frémat, Y., Diago Nebot, Pascual David, Huat, A. L., Leroy, B., Emilio, M., Hubert, A.M., Thizy, O., Andrade, L., De Batz, B., Janot-Pacheco, E., Espinosa-Lara, F., Martayan, C., Suso, J., Auvergne, M., Chaintreuil, S., Michel, E., and Catala, C.
Subjects: Esteroides, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics
Abstract: Context.The origin of the short-term variability in Be stars remains a matter of controversy. Pulsations and rotational modulation are the components of the favored hypothesis.Aims.We present our analysis of CoRoT data of the B8IIIe star HD 175869 observed during the first short run in the center direction (SRC1).Methods.We review both the instrumental effects visible in the CoRoT light curve and the analysis methods used by the CoRoT Be team. We applied these methods to the CoRoT light curve of the star HD 175869. A search for line-profile variations in the spectroscopic data was also performed. We also searched for a magnetic field, by applying the LSD technique to spectropolarimetric data.Results.The light curve exhibits low-amplitude variations of the order of 300 μ mag with a double wave shape. A frequency within the range determined for the rotational frequency and 6 of its harmonics are detected. The main frequency and its first harmonic exhibit amplitude variations of a few days. Other significant frequencies of low-amplitude from 25 to a few μmag are also found. The analysis of line profiles from ground-based spectrosc opic data does not detect an y variation. In addition, no Zeeman signature was found.Conclusions.Inhomogeneities caused by stellar activity in or just above the photosphere are proposed to produce the photometric variability detected by CoRoT in the Be star HD 175869. The hypothesis that non-radial pulsations are the origin of these variations cannot be excluded.
Published: 2009

36. Evidence for nonlinear resonant mode coupling in the Beta Cep star HD 180642 (V1449 Aql) from CoRoT space-based photometry

Author: Degroote, P., Briquet, M., Catala, C., Uytterhoeven, K., Lefever, K., Morel, T., Aerts, C., Carrier, F., Auvergne, M., Baglin, A., and Michel, E.
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: We present the CoRoT light curve of the Beta Cep star HD 180642, assembled during the first long run of the space mission, as well as archival single-band photometry. Our goal is to analyse the detailed behaviour present in the light curve and interpret it in terms of excited mode frequencies. After describing the noise properties in detail, we use various time series analysis and fitting techniques to model the CoRoT light curve, for various physical assumptions. We apply statistical goodness-of-fit criteria that allow us to select the most appropriate physical model fit to the data. We conclude that the light curve model based on nonlinear resonant frequency and phase locking provides the best representation of the data. The interpretation of the residuals is dependent on the chosen physical model used to prewhiten the data. Our observational results constitute a fruitful starting point for detailed seismic stellar modelling of this large-amplitude and evolved Beta Cep star., Comment: 13 pages, 12 figures, accepted for publication in A&A, 27 may 2009
Published: 2009
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37. Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first super-Earth with measured radius

Author: Leger, A., Rouan, D., Jodi Schneider, Barge, P., Fridlund, M., Samuel, B., Ollivier, M., Guenther, E., Deleuil, M., Deeg Hj, Auvergne, M., Alonso, R., Aigrain, S., Alapini, A., Almenara Jm, Baglin, A., Barbieri, M., Bruntt, H., Pascal Bordé, Bouchy, F., Cabrera, J., Catala, C., Carone, L., Carpano, S., Csizmadia, S., Dvorak, R., Erikson, A., Ferraz-Mello, S., Foing, B., Grasset, O., Fressin, F., Gandolfi, D., Gillon, M., Gondoin, P., Guillot, T., Hatzes, A., Hebrard, G., Jorda, L., Lammer, H., Llebaria, A., Loeillet, B., Mayor, M., Mazeh, T., Moutou, C., Patzold, M., Pont, F., Queloz, D., Rauer, H., Renner, S., Samadi, R., Shporer, A., Sotin, C., Tingley, B., Wuchterl, G., Adda, M., Agogu, P., Appourchaux, T., Ballans, H., Baron, P., Beaufort, T., Bellenger, R., Berlin, R., Bernardi, P., Blouin, D., Baudin, F., Bodin, P., Boisnard, L., Boit, L., Bonneau, F., Borzeix, S., Briet, R., Buey Jt, Butler, B., Cailleau, D., Cautain, R., Chabaud Py, Chaintreuil, S., Chiavassa, F., Costes V, Parrho Vc, Fialho Fd, Decaudin, M., Defise Jm, Djalal, S., Epstein, G., Exil Ge, Faure, C., Fenouillet, T., Gaboriaud, A., Gallic, A., Gamet, P., Gavalda, P., Grolleau, E., Gruneisen, R., Gueguen, L., Guis, V., V. Guivarc'H, Guterman, P., Hallouard, D., Hasiba, J., Heuripeau, F., Huntzinger, G., Hustaix, H., Imad, C., Imbert, C., Johlander, B., Jouret, M., Journoud, P., Karioty, F., Kerjean, L., Lafaille, V., Lafond, L., Lam-Trong, T., Landiech, P., Lapeyrere, V., Larque, T., Laudet, P., Lautier, N., Lecann, H., Lefevre, L., Leruyet, B., Levacher, P., Magnan, A., Mazy, E., Mertens, F., Mesnager Jm, Meunier Jc, Michel Jp, Monjoin, W., Naudet, D., Nguyen-Kim, K., Orcesi Jl, Ottacher, H., Perez, R., Peter, G., Plasson, P., Plesseria Jy, Pontet, B., Pradines, A., Céline Quentin, Reynaud Jl, Rolland, G., Rollenhagen, F., Romagnan, R., Russ, N., Schmidt, R., Schwartz, N., Sebbag, I., Sedes, G., Smit, H., Steller Mb, Sunter, W., Surace, C., Tello, M., Tiphene, D., Toulouse, P., Ulmer, B., Vandermarcq, O., Vergnault, E., Vuillemin, A., Laboratoire d'Astrophysique de Marseille (LAM), 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), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA)
Subjects: [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2009

38. First asteroseismic results from CoRoT. Veröffentlichungen der Kommission für Astronomie|Communications in Asteroseismology|Communications in Asteroseismology 156 156

Author: Baglin, A., Aerts, C., Barban, C., Catala, C., Michel, E., Baudin, F., Carrier, F., Auvergne, M., Briquet, M., Appourchaux, T., and al, et
Subjects: Mathematics, Physics and Space Research
Published: 2008

39. Magnetic topologies of the Herbig Ae/Be stars

Author: Alecian, E., Wade, G. A., Catala, C., Bagnulo, S., Böhm, T., Bouret, J., Donati, J., Folsom, C., Grunhut, J., Landstreet, J. D., Pascal Petit, and Silvester, J.
Subjects: Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Our recent discoveries of magnetic fields in a small number of Herbig Ae/Be (HAeBe) stars, the evolutionary progenitors of main sequence A/B stars, raise new questions about the origin of magnetic fields in the intermediate mass stars. The favoured fossil field hypothesis suggests that a few percent of magnetic pre-main sequence A/B stars should exhibit similar magnetic strengths and topologies to the magnetic Ap/Bp stars. In this talk I will present the methods that we have used to characterise the magnetic fields of the Herbig Ae/Be stars, as well as our first conclusions on the origin of magnetism in intermediate-mass stars., ASP Conference Proceedings for Astronomical Polarimetry 2008, July 6-11 2008, 5 pages
Published: 2008

40. How non-magnetic are 'non-magnetic' Herbig Ae/Be stars?

Author: Wade, G. A., Alecian, E., Catala, C., Bagnulo, S., John Landstreet, Flood, J., Böhm, T., Bouret, J. -C, Donati, J. -F, Folsom, C. P., Grunhut, J., Silvester, J., 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), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-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), Laboratoire d'Astrophysique de Marseille (LAM), 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 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), and 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)
Subjects: [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics (astro-ph), stars: magnetic fields, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, stars: pre-main sequence, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Our recent discovery of magnetic fields in a small number of Herbig Ae/Be stars has required that we survey a much larger sample of stars. From our FORS1 and ESPaDOnS surveys, we have acquired about 125 observations of some 70 stars in which no magnetic fields are detected. Using a Monte Carlo approach, we have performed statistical comparisons of the observed longitudinal fields and LSD Stokes V profiles of these apparently non-magnetic stars with a variety of field models. This has allowed us to derive general upper limits on the presence of dipolar fields in the sample, and to place realistic upper limits on undetected dipole fields which may be present in individual stars. This paper briefly reports the results of the statistical modeling, as well as field upper limits for individual stars of particular interest., Comment: 6 pages, 2 figures. In the proceedings of the "CP/Ap workshop" held in Vienna, September 2007
Published: 2008

41. Characterization of the magnetic field of the Herbig Be star HD200775

Author: Alecian, E., Catala, C., Wade, G. A., Donati, J. -F., Petit, P., Landstreet, J. D., Bagnulo, S., Boehm, T., Bouret, J. -C., Folsom, C., Grunhut, J., Silvester, J., University of Western Ontario (UWO), 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), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Centre National de la Recherche Scientifique (CNRS)-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)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, 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 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), and 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)
Subjects: [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics (astro-ph), stars: individual: HD200775, FOS: Physical sciences, instrumentation: polarimeters, stars: pre-main-sequence, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], stars: magnetic fields, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, binaries: spectroscopic
Abstract: After our recent discovery of four magnetic Herbig stars, we have decided to study in detail one of them, HD 200775, to determine if its magnetic topology is similar to that of the main sequence magnetic stars. With this aim, we monitored this star in Stokes I and V over more than two years, using the new spectropolarimeters ESPaDOnS at CFHT, and Narval at TBL. Using our data, we find that HD 200775 is a double-lined spectroscopic binary system, whose secondary seems similar, in temperature, to the primary. We determine the luminosity ratio of the system, and using the luminosity of the system found in literature, we derive the luminosity of both stars. From our measurements of the radial velocities of both stars we determine the ephemeris and the orbital parameters of the system. We have fitted 30 Stokes V profiles simultaneously, using a chi2 minimisation method, with a decentered-dipole model. The best-fit model provides a rotation period of 4.3281 d an inclination angle of 60 degrees, and a magnetic obliquity angle of 125 degrees. The polar strength of the magnetic dipole field is 1000 G, which is decentered by 0.05 R* from the center of the star. The derived magnetic field model is qualitatively identical to those commonly observed in the Ap/Bp stars, which bring strong argument in favour of the fossil field hypothesis, to explain the origin of the magnetic fields in the main sequence Ap/Bp stars. Our determination of the inclination of the rotation axis leads to a radius of the primary which is smaller than that derived from the HR diagram position. This can be explained by a larger intrinsic luminosity of the secondary relative to the primary, due to a larger circumstellar extinction of the secondary relative to the primary., Comment: Accepted for publication in MNRAS, 14 pages, 10 figures
Published: 2008

42. The seismology programme of CoRoT

Author: Michel, E., Baglin, A., Auvergne, M., and Catala, C.
Subjects: Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics
Abstract: We introduce the main lines and specificities of the CoRoT Seismology Core Programme. The development and consolidation of this programme has been made in the framework of the CoRoT Seismology Working Group. With a few illustrative examples, we show how CoRoT data will help to address various problems associated with present open questions of stellar structure and evolution., Comment: 12 pages, 16 figures
Published: 2008
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43. Magnetic geometries of Sun-like stars: impact of rotation

Author: Petit, P., Dintrans, B., Aurière, M., Catala, C., Donati, J. -F, Rim Fares, Gastine, T., Lignières, F., Morin, J., Paletou, F., Ramirez, J., Solanki, S. K., and Théado, S.
Subjects: Sun and Heliosphere
Published: 2008

44. Impact of the new solar abundances on the calibration of the PMS binary system RS Cha

Author: Alecian, E., Lebreton, Y., Goupil, M-J., Dupret, M-A., and Catala, C.
Subjects: Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Context: In a recent work, we tried to obtain a calibration of the two components of the pre-main sequence binary system RS Cha by means of theoretical stellar models. We found that the only way to reproduce the observational parameters of RS Cha with standard stellar models is to decrease the initial abundances of carbon and nitrogen derived from the GN93 solar mixture of heavy elements by a few tenths of dex. Aims: In this work, we aim to reproduce the observational properties of the RS Cha stars with stellar evolution models based on the new AGS05 solar mixture recently derived from a three-dimensional solar model atmosphere. The AGS05 mixture is depleted in carbon, nitrogen and oxygen with respect to the GN93 mixture. Methods: We calculated new stellar models of the RS Cha components using the AGS05 mixture and appropriate opacity tables. We sought models that simultaneously satisfy the observations of the two components (masses, radii, luminosities, effective temperatures and metallicity). Results: We find that it is possible to reproduce the observational data of the RS Cha stars with AGS05 models based on standard input physics. From these models, the initial helium content of the system is Y~0.255 and its age is ~9.13 +- 0.12 Myr., Research note accepted in A&A, 5 pages, 2 figures
Published: 2007

45. Synthesis of Biaryls via Decarboxylative Pd-Catalyzed Crooss-Coupling Reaction

Author: Becht, J.M., Catala, C., Le Drian, C., Wagner, A., Institut Gilbert-Laustriat : Biomolécules, Biotechnologie, Innovation Thérapeutique, Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), and Erhart, Marianne
Subjects: [CHIM.ORGA]Chemical Sciences/Organic chemistry, [CHIM.ORGA] Chemical Sciences/Organic chemistry
Published: 2007

46. Magnetic fields in Herbig Ae/Be stars

Author: Wade, G. A., Catala, C., Alecian, E., Folsom, C., Bagnulo, S., Boehm, T., Bouret, J. -C., Donati, J. -F., Drouin, D., Landstreet, J. D., 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, 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris
Subjects: Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract: Studies of stellar magnetism at the pre-main sequence phase can provide important new insights into the detailed physics of the late stages of star formation, and into the observed properties of main sequence stars. This is especially true at intermediate stellar masses, where magnetic fields are strong and globally organised, and therefore most amenable to direct study. This paper reviews recent high-precision spectropolarimetric observations of pre-main sequence Herbig Ae/Be stars, which are yielding qualitatively new information about intermediate-mass stars: the origin and evolution of their magnetic fields; the role of magnetic fields in generating their spectroscopic activity and in mediating accretion in their late formative stages; the factors influencing their rotational angular momentum; and the development and evolution of chemical peculiarity in their photospheres., 12 pages, 7 figures. Accepted by the proceedings of the 2006 conference "Magnetic Stars" of the Special Astrophysical Observatory of the Russian Academy of Sciences
Published: 2006

47. Investigating the pre-main sequence magnetic chemically peculiar system HD 72106

Author: Folsom, C. P., Wade, G. A., Hanes, D. A., Catala, C., Evelyne Alecian, Bagnulo, S., Boehm, T., C Bouret, J., F Donati, J., Landstreet, J. D., 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, 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), and Beaussier, Catherine
Subjects: [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics
Abstract: The origin of the strong magnetic fields observed in chemically peculiar Ap and Bp stars stars has long been debated. The recent discovery of magnetic fields in the intermediate mass pre-main sequence Herbig Ae and Be stars links them to Ap and Bp stars, providing vital clues about Ap and Bp stars and the origin and evolution of magnetic fields in intermediate and high mass stars. A detailed study of one young magnetic B star, HD 72106A, is presented. This star appears to be in a binary system with an apparently normal Herbig Ae star. A maximum longitudinal magnetic field strength of +391 +/- 65 G is found in HD 72106A, as are strong chemical peculiarities, with photospheric abundances of some elements ranging up to 100x above solar., Comment: 8 pages, 6 figures. Proceeding of the 2006 conference of the Special Astrophysical Observatory of the Russian Academy of Sciences
Published: 2006

48. Molecular Hydrogen in the Circumstellar Environment of Herbig Ae/Be Stars

Author: Martin, C., Deleuil, M., C. Bouret, J., Le Bourlot, J., Catala, C., Lecavelier Des Etangs, A., Vidal-Madjar, A., Roberge, A., Feldman, P.D., 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), G. Sonneborn, H. Moos, and B-G Andersson, Beaussier, Catherine, G. Sonneborn, H. Moos, and B-G Andersson, 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, 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris
Subjects: [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: We present our analysis of the molecular hydrogen in the circumstellar environment of a sample of Herbig Ae/Be stars observed with FUSE. The characteristics of H2 around Herbig Ae and Be stars gives evidence of two mechanisms of excitation. This suggests structural differences between Herbig Ae and Be stars' environments which could be explained by a faster evolution of the latter combined with stronger radiation fields.
Published: 2006

49. Characterisation of the magnetic fields of the Herbig Be stars HD 200775 and V380 0ri

Author: Evelyne Alecian, Wade, G. A., Catala, C., Bagnulo, S., Bohm, T., C Bouret, J., F Donati, J., Folsom, C. P., Landstreet, J. D., Silvester, J., 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), and Beaussier, Catherine
Subjects: [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics (astro-ph), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The origin of the magnetic fields of the chemically peculiar main sequence Ap/Bp stars is still matter of intense debate. The recent discoveries of magnetic fields in Herbig Ae/Be stars using high resolution data obtained with the spectropolarimeter ESPaDOnS at CFHT provide a strong argument in favour of the fossil field hypothesis. Using a simple oblique rotator model of a centered dipole, we fit the Stokes V LSD profiles of two of these magnetic HAeBe stars, HD 200775 and V380 Ori, as well as their variations on timescales from days to months. We find that in both cases the dipole hypothesis is acceptable and we determine the rotation period, the angle between rotation and magnetic axes and the intensity of the magnetic field at pole., Comment: 5 pages, 4 figures. Proceeding of the 2006 conference of the Special Astrophysical Observatory of the Russian Academy of Sciences
Published: 2006
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50. Calibration of the pre-main sequence RS Cha binary system

Author: Alecian, E., Goupil, M. -J., Lebreton, Y., Dupret, M. -A., and Catala, C.
Subjects: Astrophysics (astro-ph), Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Context: The calibration of binary systems with accurately known masses and/or radii provides powerful tools to test stellar structure and evolution theory and to determine the age and helium content of stars. We study the eclipsing double-lined spectroscopic binary system RS Cha, for which we have accurate observations of the parameters of both stars (masses, radii, luminosities, effective temperatures and metallicity). Aims: We have calculated several sets of stellar models for the components of the RS Cha system, with the aim of reproducing simultaneously the available observational constraints and to estimate the age and initial helium abundance of the system. Methods: Using the CESAM stellar evolution code, we model both components starting from the initial mass and metallicity and adjusting the input parameters and physics in order to satisfy the observational constraints. Results: We find that the observations cannot be reproduced if we assume that the abundance ratios are solar but they are satisfied if carbon and nitrogen are depleted in the RS Cha system with respect to the Sun. This is in accordance with the abundances observed in other young stars. The RS Cha system is in an evolutionary stage at the end of the PMS phase where models are not strongly sensitive to various physical uncertainties. However we show that the oscillations of these two stars, which have been detected, would be able to discriminate between different options in the physical description of this evolutionary phase., Comment: 9 pages, 10 figures, accepted by Astronomy & Astrophysics
Published: 2006
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