[en] 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 YË 0.255 and its age is Ë 9.13 ± 0.12 Myr.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Alecian, E.; Observatoire de Paris, LESIA, 5 place Jules Janssen, 92195 Meudon Principal Cedex, France
Lebreton, Y.; Observatoire de Paris, GEPI, UMR 8111, 5 place Jules Janssen, 92195 Meudon Principal Cedex, France
Goupil, Marie-José; Observatoire de Paris, LESIA, 5 place Jules Janssen, 92195 Meudon Principal Cedex, France
Dupret, Marc-Antoine ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique
Catala, C.; Observatoire de Paris, LESIA, 5 place Jules Janssen, 92195 Meudon Principal Cedex, France
Language :
English
Title :
Impact of the new solar abundances on the calibration of the PMS binary system RS Chamaeleontis
Alecian, E., Catala, C., van't Veer-Menneret, C., Goupil, M.-J., & Balona, L. 2005, A&A, 442, 993 (Paper I)
Alecian, E., Goupil, M.-J., Lebreton, Y., Dupret, M.-A., & Catala, C. 2006, A&A
Alexander, D. R., & Ferguson, J. W. 1994, ApJ, 437, 879
Angulo, C., Arnould, M., Rayet, M., et al. 1999, Nucl. Phys. A, 656, 3
Asplund, M., Grevesse, N., Sauval, A. J., Allende Prieto, C., & Kiselman, D. 2004, A&A, 417, 751
Asplund, M., Grevesse, N., Sauval, A. J., Allende Prieto, C., & Blomme, R. 2005a, A&A, 431, 693
Asplund, M., Grevesse, N., & Sauval, A. J. 2005b, in Cosmic Abundances as Records of Stellar Evolution and Nucleosynthesis, ed. T. G. Barnes, III & F. N. Bash, ASP Conf. Ser., 336, 25
Basu, S., & Antia, H. M. 2004, ApJ, 606, L85
Böhm-Vitense, E. 1958, Z. Astrophys., 46, 108
Clausen, J. V., & Nordstrom, B. 1980, A&A, 83, 339
Daflon, S., Cunha, K., & Butler, K. 2004, ApJ, 604, 362
D'Antona, F., & Mazzitelli, I. 1998, in Brown Dwarfs and Extrasolar Planets, ed. R. Rebolo, E. L. Martin, & M. R. Zapatero Osorio, ASP Conf. Ser., 134, 442
Ferguson, J. W., Alexander, D. R., Allard, F., et al. 2005, ApJ, 623, 585
Grevesse, N., & Noels, A. 1993, Origin and Evolution of the Elements, ed. N. Prantzos, E. Langioni-flam, & M. Classe (Cambridge Univ. Press), 14
Iglesias, C. A., & Rogers, F. J. 1996, ApJ, 464, 943
Kurucz, R. 1993, ATLAS9 Stellar Atmosphere Programs and 2 km s -1 grid (Cambridge, Mass.: Smithsonian Astrophysical Observatory)
Lawson, W. A., Crause, L. A., Mamajek, E. E., & Feigelson, E. D. 2001, MNRAS, 321, 57
Lebreton, Y. 2005, in The Three-Dimensional Universe with Gaia, ed. C. Turon, K. S. O'Flaherty, & M. A. C. Perryman, ESA SP-576, 493
Lyo, A.-R., Lawson, W. A., & Bessell, M. S. 2004, MNRAS, 355, 363
Lyo, A.-R., Song, I., Lawson, W. A., Bessell, M. S., & Zuckerman, B. 2006, MNRAS, 368, 1451
