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648 results on '"Dupret, M. A."'

102. Apsidal motion in NGC 6231: Sounding the internal structure of massive stars.

Author

Rosu, S., Rauw, G., Dupret, M.-A., Noels, A., and Farnir, M.

Subjects
STELLAR evolution, DENSITY of stars, SUPERGIANT stars, BINARY stars, OPEN clusters of stars
Abstract

The young open cluster NGC 6231 hosts a rich population of O-type binary stars. We study several of these eccentric short-period massive eclipsing binaries and assess their fundamental parameters. The properties of these systems make them interesting targets to study tidally induced apsidal motion. The analysis of apsidal motion offers a powerful means to obtain information about the internal structure of the stars. Indeed, since the rate of apsidal motion in a binary system is proportional to the internal structure constants of the stars composing it, its value gives direct insight into the internal structure and evolutionary state of these stars. Stellar evolution models are constructed based on the observationally-determined fundamental parameters and a theoretical rate of apsidal motion is inferred. The results are striking: Adopting standard stellar evolution models yields a theoretical rate of apsidal motion much larger than the observational value. This discrepancy results from the standard models predicting too low an efficiency of internal mixing and thus too homogenous stars in terms of density. By enforcing the theoretical rates of apsidal motion to match the observational values, enhanced mixing is required, through a large overshooting parameter and/or additional turbulent/rotational mixing. Our analysis leads to the conclusion that the chemically mixed cores in those massive stars must be more extended than anticipated from standard models. [ABSTRACT FROM AUTHOR]

Published
2022
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109. Stellar acoustic radii and ages from seismic inversion techniques

Author

Buldgen G., Reese D. R., Dupret M. A., and Samadi R.

Subjects
Physics, QC1-999
Abstract

Determining stellar characteristics such as the radius, mass or age is crucial and asteroseismology is currently the most promising tool to provide these results accurately. We extend the SOLA inversion technique to new global characteristics in addition to the mean density [2] and apply our methodology to the acoustic radius and an age indicator based on the sound speed derivative. The results from SOLA inversions are compared with estimates based on the small and large frequency separations for several test cases. We show that SOLA inversions yield more accurate results than other techniques which are more sensitive to surface effects.

Published
2015
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113. HAYDN -- High-precision AsteroseismologY of DeNse stellar fields (ESA Voyage 2050 White Paper)

Author

Miglio, A, Girardi, L, Grundahl, F, Mosser, B, Bastian, N, Bragaglia, A, Brogaard, K, Buldgen, G, Chantereau, W, Chaplin, B, Chiappini, C, Dupret, M-A, Eggenberger, P, Gieles, M, Izzard, R, Kawata, D, Karoff, C, Lagarde, N, Mackereth, T, Magrin, D, Meynet, G, Michel, E, Montalban, J, Nascimbeni, V, Noels, A, Piotto, G, Ragazzoni, R, Soszynski, I, Tolstoy, E, Toonen, S, Triaud, A, and Vincenzo, F

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics of Galaxies (astro-ph.GA), 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 - Astrophysics of Galaxies, QC, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, QB
Abstract

In the last decade, the Kepler and CoRoT space-photometry missions have demonstrated the potential of asteroseismology as a novel, versatile and powerful tool to perform exquisite tests of stellar physics, and to enable precise and accurate characterisations of stellar properties, with impact on both exoplanetary and Galactic astrophysics. Based on our improved understanding of the strengths and limitations of such a tool, we argue for a new small/medium space mission dedicated to gathering high-precision, high-cadence, long photometric series in dense stellar fields. Such a mission will lead to breakthroughs in stellar astrophysics, especially in the metal poor regime, will elucidate the evolution and formation of open and globular clusters, and aid our understanding of the assembly history and chemodynamics of the Milky Way's bulge and few nearby dwarf galaxies., White paper submitted in response to Voyage 2050 long-term plan in the ESA Science Programme, now published in Experimental Astronomy, see https://link.springer.com/article/10.1007/s10686-021-09711-1

Published
2019

114. Comprehensive stellar seismic analysis : A preliminary application of Whosglad to 16 Cygni system

Author

Farnir, M., Dupret, M.-A., Salmon, S.J.A.J., Noels, A., and Buldgen, G

Subjects
Giltch, Astrophysics - Solar and Stellar Astrophysics, Heium abundance, Asteroseismology, FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Numerical method, 16 Cigni sytsem, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics::Geophysics
Abstract

We present a first application of Whosglad method to the components A and B of the 16 Cygni system. The method was developed to provide a comprehensive analysis of stellar oscillation spectra. It defines new seismic indicators which are as uncorrelated and precise as possible and hold detailed information about stellar interiors. Such indicators, as illustrated in the present paper, may be used to generate stellar models via forward seismic modeling. Finally, seismic constraints retrieved by the method provide realistic stellar parameters., Errors in the entries for Y_f in Table 2 have been corrected., {"references":["Adelberger, E. G., García, A., Robertson, R. G. H., Snover, K. A., Balantekin, A. B., et al. 2011, Reviews of Modern Physics, 83, 195.","Asplund, M., Grevesse, N., Sauval, A. J., & Scott, P. 2009, ARA&A, 47, 481.","Baglin, A., Auvergne, M., Barge, P., Deleuil, M., Michel, E., et al. 2009, In Transiting Planets, edited by F. Pont, D. Sasselov, & M. J. Holman, IAU Symposium, vol. 253, pp. 71–81.","Basu, S., Mazumdar, A., Antia, H. M., & Demarque, P. 2004, MNRAS, 350, 277.","Borucki, W. J., Koch, D., Basri, G., Batalha, N. M., Brown, T., et al. 2010, In American Astronomical Society Meeting Abstracts #215, Bulletin of the American Astronomical Society, vol. 42, p. 215.","Cassisi, S., Salaris, M., & Irwin, A. W. 2003, ApJ, 588, 862.","Cox, J. P. & Giuli, R. T. 1968, Principles of stellar structure .","Davies, G. R., Chaplin, W. J., Farr, W. M., García, R. A., Lund, M. N., et al. 2015, MNRAS, 446, 2959.","Farnir, M., Dupret, M.-A., Salmon, S. J. A. J., Noels, A., & Buldgen, G. 2018 submitted, A&A.","Ferguson, J. W., Alexander, D. R., Allard, F., Barman, T., Bodnarik, J. G., et al. 2005, ApJ, 623, 585.","Gough, D. O. 1986, Highlights of Astronomy, 7, 283.","Gough, D. O. 1990, In Progress of Seismology of the Sun and Stars, edited by Y. Osaki & H. Shibahashi, Lecture Notes in Physics, Berlin Springer Verlag, vol. 367, p. 283.","Gram, J. P. 1883, Journal für die reine und angewandte Mathematik, 94, 41.","Grec, G., Fossat, E., & Pomerantz, M. A. 1983, SoPh, 82, 55.","Grevesse, N. & Noels, A. 1993, In Origin and Evolution of the Elements, edited by N. Prantzos, E. Vangioni-Flam, & M. Casse, pp. 15–25.","Houdek, G. & Gough, D. O. 2007, MNRAS, 375, 861.","Iglesias, C. A. & Rogers, F. J. 1996, ApJ, 464, 943.","Kjeldsen, H., Bedding, T. R., & Christensen-Dalsgaard, J. 2008, ApJ, 683, L175.","Metcalfe, T. S., Chaplin, W. J., Appourchaux, T., García, R. A., Basu, S., et al. 2012, ApJ, 748, L10.","Monteiro, M. J. P. F. G., Christensen-Dalsgaard, J., & Thompson, M. J. 2000, MNRAS, 316, 165.","Ramírez, I., Meléndez, J., & Asplund, M. 2009, A&A, 508, L17.","Roxburgh, I. W. & Vorontsov, S. V. 2003, A&A, 411, 215.","Schmidt, E. 1907, Mathematische Annalen, 63, 433.","Scuflaire, R., Montalbán, J., Théado, S., Bourge, P.-O., Miglio, A., et al. 2008a, Ap&SS, 316, 149.","Scuflaire, R., Théado, S., Montalbán, J., Miglio, A., Bourge, P.-O., et al. 2008b, Ap&SS, 316, 83.","Sonoi, T., Samadi, R., Belkacem, K., Ludwig, H.-G., Caffau, E., et al. 2015, A&A, 583, A112.","Thoul, A. A., Bahcall, J. N., & Loeb, A. 1994, ApJ, 421, 828.","Verma, K., Faria, J. P., Antia, H. M., Basu, S., Mazumdar, A., et al. 2014, ApJ, 790, 138.","Vorontsov, S. V. 1988, In Advances in Helio- and Asteroseismology, edited by J. Christensen-Dalsgaard & S. Frandsen, IAU Symposium, vol. 123, p. 151.","White, T. R., Huber, D., Maestro, V., Bedding, T. R., Ireland, M. J., et al. 2013, MNRAS, 433, 1262."]}

Published
2018
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115. Amplitudes of solar-like oscillations in red giants: Departures from the quasi-adiabatic approximation

Author

Barban C., Ludwig H.-G., Goupil M.J., Dupret M.-A., Belkacem K., Samadi R., Baudin F., and Caffau E.

Subjects
Physics, QC1-999
Abstract

CoRoT and Kepler measurements reveal us that the amplitudes of solar-like oscillations detected in red giant stars scale from stars to stars in a characteristic way. This observed scaling relation is not yet fully understood but constitutes potentially a powerful diagnostic about mode physics. Quasi-adiabatic theoretical scaling relations in terms of mode amplitudes result in systematic and large differences with the measurements performed for red giant stars. The use of a non-adiabatic intensity-velocity relation derived from a non-adiabatic pulsation code significantly reduces the discrepancy with the CoRoT measurements. The origin of the remaining difference is still unknown. Departure from adiabatic eigenfunction is a very likely explanation that is investigated in the present work using a 3D hydrodynamical model of the surface layers of a representative red giant star.

Published
2013
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116. Calibration Of The Mixing Length Of The Mlt And Fst Models Using 3D Hydrodynamical Models

Author

Sonoi, T., Ludwig, H. -G., Dupret, M. -A., Montalban, J., Samadi, R., Belkacem, K., Caffau, E., and Goupil, M. -J.

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

The high-quality data of solar-like oscillations by CoRoT and Kepler would enable us to precisely determine stellar characteristics. To make the best of such data, we need stellar models with precise near-surface structure, which significantly impacts on solar-like oscillation frequencies. The mixing length of convection models is a key factor for the near-surface structure. We calibrated values of the mixing length parameters of the classical mixing length theory (MLT) and the full spectrum turbulence (FST) model based on 3D CO5BOLD models. The parameter values are found to vary substantially with effective temperature and surface gravity. It implies that the calibrated parameter values should be implemented into evolution codes instead of fixing the parameter values during the evolution.

Published
2018
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121. Seismic inversion of the solar entropy

Author

Buldgen, G., primary, Salmon, S. J. A. J., additional, Noels, A., additional, Scuflaire, R., additional, Reese, D. R., additional, Dupret, M.-A., additional, Colgan, J., additional, Fontes, C. J., additional, Eggenberger, P., additional, Hakel, P., additional, Kilcrease, D. P., additional, and Turck-Chièze, S., additional

Published
2017
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122. Lessons Learned from the Design and Operation of a 300 kWp PV System with Full Self-Consumption of the Energy Produced

Author

Gaiddon, B., Joos, M., Thebault, A., Derobert, C., Debray, N., Dupret, M., and Rozel, B.

Subjects
Operation of PV Systems, Operation, Performance, Reliability and Sustainability of Photovoltaics
Abstract

32nd European Photovoltaic Solar Energy Conference and Exhibition; 2110-2112, This article presents the lessons learned from the design and operation of a 300 kWp PV system installed, during spring and summer 2015, on the roof of a new logistic building located in western France. As this building is equipped with refrigerating units, thus with a high power consumption during hot and sunny days, it has been decided to consume the energy produced on-site without any regulated feed-in tariff but with a B-to-B contract, a first of its kind in France. In order to not inject power into the local MV distribution grid, the active power management feature of PV inverters has been implemented, also a first of its kind in France. This paper gives a summary of the detailed on-going monitoring campaign that aims to check if the actual power consumption of the site matches the consumption forecast and if the active power management feature of PV inverters has a significant impact on the total energy generation of this PV system.

Published
2016
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123. Inversions of the Ledoux discriminant: a closer look at the tachocline

Author

Buldgen, Gaël, primary, Salmon, S. J. A. J., additional, Godart, M., additional, Noels, A., additional, Scuflaire, R., additional, Dupret, M. A., additional, Reese, D. R., additional, Colgan, J., additional, Fontes, C. J., additional, Eggenberger, P., additional, Hakel, P., additional, Kilcrease, D. P., additional, and Richard, O., additional

Published
2017
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125. PLATO as it is: A legacy mission for Galactic archaeology

Author

Miglio, A., primary, Chiappini, C., additional, Mosser, B., additional, Davies, G. R., additional, Freeman, K., additional, Girardi, L., additional, Jofré, P., additional, Kawata, D., additional, Rendle, B. M., additional, Valentini, M., additional, Casagrande, L., additional, Chaplin, W. J., additional, Gilmore, G., additional, Hawkins, K., additional, Holl, B., additional, Appourchaux, T., additional, Belkacem, K., additional, Bossini, D., additional, Brogaard, K., additional, Goupil, M.‐J., additional, Montalbán, J., additional, Noels, A., additional, Anders, F., additional, Rodrigues, T., additional, Piotto, G., additional, Pollacco, D., additional, Rauer, H., additional, Prieto, C. Allende, additional, Avelino, P. P., additional, Babusiaux, C., additional, Barban, C., additional, Barbuy, B., additional, Basu, S., additional, Baudin, F., additional, Benomar, O., additional, Bienaymé, O., additional, Binney, J., additional, Bland‐Hawthorn, J., additional, Bressan, A., additional, Cacciari, C., additional, Campante, T. L., additional, Cassisi, S., additional, Christensen‐Dalsgaard, J., additional, Combes, F., additional, Creevey, O., additional, Cunha, M. S., additional, Jong, R. S., additional, Laverny, P., additional, Degl'Innocenti, S., additional, Deheuvels, S., additional, Depagne, É., additional, Ridder, J., additional, Matteo, P. Di, additional, Mauro, M. P. Di, additional, Dupret, M.‐A., additional, Eggenberger, P., additional, Elsworth, Y., additional, Famaey, B., additional, Feltzing, S., additional, García, R. A., additional, Gerhard, O., additional, Gibson, B. K., additional, Gizon, L., additional, Haywood, M., additional, Handberg, R., additional, Heiter, U., additional, Hekker, S., additional, Huber, D., additional, Ibata, R., additional, Katz, D., additional, Kawaler, S. D., additional, Kjeldsen, H., additional, Kurtz, D. W., additional, Lagarde, N., additional, Lebreton, Y., additional, Lund, M. N., additional, Majewski, S. R., additional, Marigo, P., additional, Martig, M., additional, Mathur, S., additional, Minchev, I., additional, Morel, T., additional, Ortolani, S., additional, Pinsonneault, M. H., additional, Plez, B., additional, Moroni, P. G. Prada, additional, Pricopi, D., additional, Recio‐Blanco, A., additional, Reylé, C., additional, Robin, A., additional, Roxburgh, I. W., additional, Salaris, M., additional, Santiago, B. X., additional, Schiavon, R., additional, Serenelli, A., additional, Sharma, S., additional, Aguirre, V. Silva, additional, Soubiran, C., additional, Steinmetz, M., additional, Stello, D., additional, Strassmeier, K. G., additional, Ventura, P., additional, Ventura, R., additional, Walton, N. A., additional, and Worley, C. C., additional

Published
2017
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129. The IACOB project

Author

Godart, M., primary, Simón-Díaz, S., additional, Herrero, A., additional, Dupret, M. A., additional, Grötsch-Noels, A., additional, Salmon, S. J. A. J., additional, and Ventura, P., additional

Published
2016
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131. Observational calibration of the projection factor of Cepheids

Author

Belkacem, K., Marques, J., Goupil, M., Sonoi, T., Ouazzani, R., Dupret, M., Mathis, S., Mosser, B., Grosjean, M., Benisty, M., Juhasz, A., Boccaletti, A., Avenhaus, H., Milli, J., Thalmann, C., Dominik, C., Pinilla, P., Buenzli, E., Pohl, A., Beuzit, J.-L., Birnstiel, T., De Boer, J., Bonnefoy, M., Chauvin, G., Christiaens, V., Garufi, A., Grady, C., Henning, T., Huélamo, N., Isella, A., Langlois, M., Menard, F., Mouillet, D., Olofsson, J., Pantin, E., Pinte, C., Pueyo, L., Breitfelder, J., Kervella, P., Mérand, A., Gallenne, A., Szabados, L., Anderson, R., Willson, M., Le Bouquin, J.-B., 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), Laboratoire d'automatique et de génie des procédés (LAGEP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, 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), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute for Particle Physics and Astrophysics [ETH Zürich] (IPA), Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Institute of Astronomy [ETH Zürich], Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Ludwig-Maximilians-Universität München (LMU), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL), Departamento de Astronomía, Universidad de Chile, Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), 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)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, School of Physics, University of Exeter, Space Telescope Science Institute (STSci), Laboratoire Franco-Chilien d'Astronomie (LFCA), Universidad de Concepción [Chile]-Pontificia Universidad Católica de Chile (UC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Universidad de Chile, Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), 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), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Spain] (CSIC), 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]Physics [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2015

132. Calibration of mixing-length parameter α for MLT and FST models by matching with CO5BOLD models.

Author

Sonoi, T., Ludwig, H.-G., Dupret, M.-A., Montalbán, J., Samadi, R., Belkacem, K., Caffau, E., and Goupil, M.-J.

Subjects
OSCILLATIONS, PARAMETERS (Statistics), ENTROPY, CALIBRATION, STELLAR evolution
Abstract

Context. Space observations by the CoRoT and Kepler missions have provided a wealth of high-quality seismic data for a large number of stars from the main sequence to the red giant phases. One main goal of these missions is to take advantage of the rich spectra of solar-like oscillations to perform precise determinations of stellar characteristic parameters. To make the best of such data, we need theoretical stellar models with a precise near-surface structure since a near-surface structure of a solar-like star has significant influence on solar-like oscillation frequencies. The mixing-length parameter is a key factor to determine the near-surface structure of stellar models. In current versions of the convection formulations used in stellar evolution codes, the mixing-length parameter is a free parameter that needs to be properly specified. Aims. We aim at determining appropriate values of the mixing-length parameter, α, to be used consistently with the adopted convection formulation when computing stellar evolution models across the Hertzsprung–Russell diagram. This determination is based on 3D hydrodynamical simulation models. Methods. We calibrated α values by matching entropy profiles of 1D envelope models with those of hydrodynamical 3D models of solar-like stars produced by the CO5BOLD code. For such calibration, previous works concentrated on the classical mixing-length theory (MLT). We also analyzed full spectrum turbulence (FST) models. To construct the atmosphere in the 1D models, we used the Eddington gray T(τ) relation and that with the solar-calibrated Hopf-like function. Results. For both MLT and FST models with a mixing length l = αHp, calibrated α values increase with increasing surface gravity or decreasing effective temperature. For the FST models, we carried out an additional calibration using an α* value defined as l = rtop − r + α*Hp, top, where α* is found to increase with surface gravity and effective temperature. We provide tables of the calibrated α values across the Teff–log g plane for solar metallicity. By computing stellar evolution with varying α based on our 3D α calibration, we find that the change from solar α to varying α shifts evolutionary tracks particularly for the FST model. As for the correspondence to the 3D models, the solar Hopf-like function generally gives a photospheric-minimum entropy closer to a 3D model than the Eddington T(τ). The structure below the photosphere depends on the adopted convection model. However, we cannot obtain a definitive conclusion about which convection model gives the best correspondence to the 3D models. This is because each 1D physical quantity is related via an equation of state (EoS), but it is not the case for the averaged 3D quantities. Although the FST models with l = rtop − r + α*Hp, top are found to give the oscillation frequencies closest to the solar observed frequencies, their acoustic cavities are formed with compensatory effects between deviating density and temperature profiles near the top of the convective envelope. In future work, an appropriate treatment of the top part of the 1D convective envelope is necessary, for example, by considering turbulent pressure and overshooting. [ABSTRACT FROM AUTHOR]

Published
2019
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136. 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

137. Pulsations of rapidly rotating stars

Author

Ouazzani, R.-M., Dupret, M.-A., Reese, 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, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2012

139. Amplitudes of solar-like oscillations in red giant stars

Author

Samadi, R., Belkacem, K., Dupret, M.-A., Ludwig, H.-G., Baudin, F., Caffau, E., Goupil, M.-J., Barban, C., 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), and Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris

Subjects
[PHYS]Physics [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2012

140. Damping rates of solar-like oscillations across the HR diagram

Author

Belkacem, K., Dupret, M., Baudin, F., Appourchaux, T., Marques, J., Samadi, R., 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), 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), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'automatique et de génie des procédés (LAGEP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université de Lyon-Université de Lyon-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2012

141. Towards Precise Asteroseismology of Solar-Like Stars

Author

Grigahcene, A, Dupret, M-A, Sousa, SG, Monteiro, MJPFG, Garrido, R, Scuflaire, R, Gabriel, M, and Faculdade de Ciências

Subjects
Astronomia, Física, Physical sciences [Natural sciences], Física [Ciências exactas e naturais], Astronomy, Physical sciences
Published
2012

142. Towards precise asteroseismology of solar-like stars

Author

Grigahc��ne, A., Dupret, M. -A., Sousa, S. G., Monteiro, M. J. P. F. G., Garrido, R., Scuflaire, R., and Gabriel, M.

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

Adiabatic modeling of solar-like oscillations cannot exceed a certain level of precision for fitting individual frequencies. This is known as the problem of near surface effects on the mode physics. We present a theoretical study which addresses the problem of frequency precision in non-adiabatic models using a time-dependent convection treatment. We find that the number of acceptable model solutions is significantly reduced and more precise constraints can be imposed on the models. Results obtained for a specific star (beta Hydri) lead to very good agreement with both global and local seismic observables. This indicates that the accuracy of model fitting to seismic data is greatly improved when a more complete description of the interaction between convection and pulsation is taken into account., 4 pages, 2 figures. To be published in Astrophysics and Space Science Proceedings series (ASSP). Proceedings of the "20th Stellar Pulsation Conference Series: Impact of new instrumentation and new insights in stellar pulsations", 5-9 September 2011, Granada, Spain

Published
2011

148. Are the stars of a new class of variability detected in NGC~3766 fast rotating SPB stars?

Author

Salmon, S. J. A. J., Montalbán, J., Reese, D. R., Dupret, M. -A., Eggenberger, P., Salmon, S. J. A. J., Montalbán, J., Reese, D. R., Dupret, M. -A., and Eggenberger, P.

Abstract

A recent photometric survey in the NGC~3766 cluster led to the detection of stars presenting an unexpected variability. They lie in a region of the Hertzsprung-Russell (HR) diagram where no pulsation are theoretically expected, in between the $\delta$ Scuti and slowly pulsating B (SPB) star instability domains. Their variability periods, between $\sim$0.1--0.7~d, are outside the expected domains of these well-known pulsators. The NCG~3766 cluster is known to host fast rotating stars. Rotation can significantly affect the pulsation properties of stars and alter their apparent luminosity through gravity darkening. Therefore we inspect if the new variable stars could correspond to fast rotating SPB stars. We carry out instability and visibility analysis of SPB pulsation modes within the frame of the traditional approximation. The effects of gravity darkening on typical SPB models are next studied. We find that at the red border of the SPB instability strip, prograde sectoral (PS) modes are preferentially excited, with periods shifted in the 0.2--0.5~d range due to the Coriolis effect. These modes are best seen when the star is seen equator-on. For such inclinations, low-mass SPB models can appear fainter due to gravity darkening and as if they were located between the $\delta$~Scuti and SPB instability strips., Comment: 6 pages, 2 figures, to appear in the proceedings of the IAU Symposium 307, New windows on massive stars: asteroseismology, interferometry, and spectropolarimetry

Published
2014
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149. Theoretical power spectra of mixed modes in low mass red giant stars

Author

Grosjean, M., Dupret, M. -A., Belkacem, K., Montalban, J., Samadi, R., Mosser, B., Grosjean, M., Dupret, M. -A., Belkacem, K., Montalban, J., Samadi, R., and Mosser, B.

Abstract

CoRoT and Kepler observations of red giant stars revealed very rich spectra of non-radial solar-like oscillations. Of particular interest was the detection of mixed modes that exhibit significant amplitude, both in the core and at the surface of the stars. It opens the possibility of probing the internal structure from their inner-most layers up to their surface along their evolution on the red giant branch as well as on the red-clump. Our objective is primarily to provide physical insight into the physical mechanism responsible for mixed-modes amplitudes and lifetimes. Subsequently, we aim at understanding the evolution and structure of red giants spectra along with their evolution. The study of energetic aspects of these oscillations is also of great importance to predict the mode parameters in the power spectrum. Non-adiabatic computations, including a time-dependent treatment of convection, are performed and provide the lifetimes of radial and non-radial mixed modes. We then combine these mode lifetimes and inertias with a stochastic excitation model that gives us their heights in the power spectra. For stars representative of CoRoT and Kepler observations, we show under which circumstances mixed modes have heights comparable to radial ones. We stress the importance of the radiative damping in the determination of the height of mixed modes. Finally, we derive an estimate for the height ratio between a g-type and a p-type mode. This can thus be used as a first estimate of the detectability of mixed-modes.

Published
2014
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150. The blue-edge problem of the V1093 Her instability strip revisited using evolutionary models with atomic diffusion

Author

Bloemen, S., Hu, Haili, Aerts, C., Dupret, M. A., Østensen, R. H., Degroote, P., Müller-Ringat, E., Rauch, T., Bloemen, S., Hu, Haili, Aerts, C., Dupret, M. A., Østensen, R. H., Degroote, P., Müller-Ringat, E., and Rauch, T.

Abstract

We have computed a new grid of evolutionary subdwarf B star (sdB) models from the start of central He burning, taking into account atomic diffusion due to radiative levitation, gravitational settling, concentration diffusion, and thermal diffusion. We have computed the non-adiabatic pulsation properties of the models and present the predicted p-mode and g-mode instability strips. In previous studies of the sdB instability strips, artificial abundance enhancements of Fe and Ni were introduced in the pulsation driving layers. In our models, the abundance enhancements of Fe and Ni occur naturally, eradicating the need to use artificial enhancements. We find that the abundance increases of Fe and Ni were previously underestimated and show that the instability strip predicted by our simulations solves the so-called blue edge problem of the subdwarf B star g-mode instability strip. The hottest known g-mode pulsator, KIC 10139564, now resides well within the instability strip {even when only modes with low spherical degrees (l<=2) are considered., Comment: 7 pages, 7 figures. Accepted for publication in Astronomy & Astrophysics

Published
2014
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