stars: solar-type; stars: interiors; stars: rotation; stars: oscillations; stars: magnetic field
Abstract :
[en] Context. Observations of solar-like oscillations obtained either from the ground or from space stimulated the study of the effects of various physical processes on the modelling of solar-type stars. <BR /> Aims: The influence of rotational mixing on the evolution and asteroseismic properties of solar-type stars is studied. <BR /> Methods: Global and asteroseismic properties of models of solar-type stars computed with and without a comprehensive treatment of shellular rotation are compared. The effects of internal magnetic fields are also discussed in the framework of the Tayler-Spruit dynamo. <BR /> Results: Rotational mixing changes the global properties of a solar-type star with a significant increase of the effective temperature resulting in a shift of the evolutionary track to the blue part of the HR diagram. These differences observed in the HR diagram are related to changes of the chemical composition, because rotational mixing counteracts the effects of atomic diffusion leading to larger helium surface abundances for rotating models than for non-rotating ones. Higher values of the large frequency separation are then found for rotating models than for non-rotating ones at the same evolutionary stage, because the increase of the effective temperature leads to a smaller radius and hence to an increase of the stellar mean density. In addition to changing the global properties of solar-type stars, rotational mixing also has a considerable impact on the structure and chemical composition of the central stellar layers by bringing fresh hydrogen fuel to the central stellar core, thereby enhancing the main-sequence lifetime. The increase of the central hydrogen abundance together with the change of the chemical profiles in the central layers result in a significant increase of the values of the small frequency separations and of the ratio of the small to large separations for models including shellular rotation. This increase is clearly seen for models with the same age sharing the same initial parameters except for the inclusion of rotation as well as for models with the same global stellar parameters and in particular the same location in the HR diagram. By computing rotating models of solar-type stars including the effects of a dynamo that possibly occurs in the radiative zone, we find that the efficiency of rotational mixing is strongly reduced when the effects of magnetic fields are taken into account, in contrast to what happens in massive stars.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Eggenberger, P.; Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland
Meynet, G.; Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland
Maeder, A.; Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland
Miglio, A.; Institut d'Astrophysique et de Géophysique de l'Université de Liège, 17 allée du 6 Août, 4000 Liège, Belgium
Montalban Iglesias, Josefa ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Carrier, F.; Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium
Mathis, S.; Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot, DAPNIA/SAp, 91191 Gif-sur-Yvette Cedex, France ; LUTH, Observatoire de Paris, CNRS, Université Paris Diderot, 5 place Jules Janssen, 92195 Meudon, France
Charbonnel, C.; Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland ; Laboratoire d'Astrophysique de Toulouse-Tarbes, CNRS UMR 5572, Université Toulouse III, 31400 Toulouse, France
Talon, S.; Département de Physique, Université de Montréal, Montréal PQ H3C 3J7, Canada )
Language :
English
Title :
Effects of rotational mixing on the asteroseismic properties of solar-type stars
Basu, S., Mazumdar, A., Antia, H.M., & Demarque, P. 2004, MNRAS, 350, 277
Bedding, T. R., & Kjeldsen, H. 2008, in 14th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, ed. G. van Belle, ASP Conf. Ser., 384, 21
Bedding, T. R., Butler, R. P., Carrier, F., et al. 2006, ApJ, 647, 558
Bouchy, F., & Carrier, F. 2002, A&A, 390, 205
Bouvier, J., Forestini, M., & Allain, S. 1997, A&A, 326, 1023
Brown, T. M., Christensen-Dalsgaard, J., Dziembowski, W. A., et al. 1989, ApJ, 343, 526
Carrier, F., & Eggenberger, P. 2006, A&A, 450, 695
Carrier, F., Eggenberger, P., D'Alessandro, A., & Weber, L. 2005, New Astron., 10, 315
Chaboyer, B., & Zahn, J.-P. 1992, A&A, 253, 173
Chaboyer, B., Demarque, P., & Pinsonneault, M. H. 1995, ApJ, 441, 865
Chaplin, W. J., Appourchaux, T., Elsworth, Y., et al. 2010, ApJ, 713, L169
Charbonneau, P., & MacGregor, K. B. 1993, ApJ, 417, 762
Charbonnel, C., & Talon, S. 2005, Science, 309, 2189
Christensen-Dalsgaard, J. 2008, Ap&SS, 316, 113
Couvidat, S., García, R. A., Turck-Chièze, S., et al. 2003, ApJ, 597, L77
Decressin, T., Mathis, S., Palacios, A., et al. 2009, A&A, 495, 271
Denissenkov, P. A., & Pinsonneault, M. 2007, ApJ, 655, 1157
Eddington, A. S. 1925, The Observatory, 48, 73
Eggenberger, P., Maeder, A., & Meynet, G. 2005, A&A, 440, L9
Eggenberger, P., Meynet, G., Maeder, A., et al. 2008, Ap&SS, 316, 43
Floranes, H. O., Christensen-Dalsgaard, J., & Thompson, M. J. 2005, MNRAS, 356, 671
Gellert, M., Rüdiger, G., & Elstner, D. 2008, A&A, 479, L33
Gough, D. O. 2002, in Stellar Structure and Habitable Planet Finding, ed. B. Battrick, F. Favata, I. W. Roxburgh, & D. Galadi, ESA SP, 485, 65
Grevesse, N., & Noels, A. 1993, in Origin and evolution of the elements: Proceedings of a symposium in honour of H. Reeves, held in Paris, June 22-25, 1992, ed. N. Prantzos, E. Vangioni-Flam, & M. Casse (Cambridge, England: Cambridge University Press), 14
Houdek, G., & Gough, D. O. 2007, MNRAS, 375, 861
Kawaler, S. D. 1988, ApJ, 333, 236
Kosovichev, A. G., Schou, J., Scherrer, P. H., et al. 1997, Sol. Phys., 170, 43
Kumar, P., & Quataert, E. J. 1997, ApJ, 475, L143
Maeder, A. 2003, A&A, 399, 263
Maeder, A. 2009, Physics, Formation and Evolution of Rotating Stars (Berlin, Heidelberg: Springer)
Matias, J., & Zahn, J.-P. 1998, in Sounding solar and stellar interiors, ed. J. Provost, & F. X. Schmider, IAU Symp. 181, poster volume
Mestel, L., & Weiss, N. O. 1987, MNRAS, 226, 123
Miglio, A., Christensen-Dalsgaard, J., di Mauro, M. P., Monteiro, M. J. P. F. G., & Thompson, M. J. 2003, in Asteroseismology Across the HR Diagram, ed. M. J. Thompson, M. S. Cunha, & M. J. P. F. G. Monteiro, 537
Monteiro, M. J. P. F. G., & Thompson, M. J. 1998, in New Eyes to See Inside the Sun and Stars, ed. F.-L. Deubner, J. Christensen-Dalsgaard, & D. Kurtz, IAU Symp., 185, 317
Mosser, B., Michel, E., Appourchaux, T., et al. 2009, A&A, 506, 33
