[en] We present a seismic study of the beta Cephei star theta Ophiuchi. Our analysis is based on the observation of one radial mode, one rotationally split l = 1 triplet and three components of a rotationally split l = 2 quintuplet for which the m values were well identified by spectroscopy. We identify the radial mode as fundamental, the triplet as p(1) and the quintuplet as g(1). Our non-local thermodynamic equilibrium abundance analysis results in a metallicity and CNO abundances in full agreement with the most recent updated solar values. With X epsilon [0.71, 0.7211] and Z epsilon [0.009, 0.015], and using the Asplund et al. mixture but with a Ne abundance about 0.3 dex larger, the matching of the three independent modes enables us to deduce constrained ranges for the mass (M = 8.2 +/- 0.3 M circle dot) and central hydrogen abundance (X-c = 0.38 +/- 0.02) of theta Oph and to prove the occurrence of core overshooting (alpha(ov) = 0.44 +/- 0.07). We also derive an equatorial rotation velocity of 29 +/- 7 km s(-1). Moreover, we show that the observed non-equidistance of the l = 1 triplet can be reproduced by the second-order effects of rotation. Finally, we show that the observed rotational splitting of two modes cannot rule out a rigid rotation model.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Briquet, Maryline ; Katholieke Universiteit Leuven, Departement Natuurkunde en Sterrenkunde, Instituut voor Sterrenkunde, Celestijnenlaan 200D, 3001 Leuven, Belgium
Morel, Thierry ; Katholieke Universiteit Leuven, Departement Natuurkunde en Sterrenkunde, Instituut voor Sterrenkunde, Celestijnenlaan 200D, 3001 Leuven, Belgium
Thoul, Anne ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Scuflaire, Richard ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Evol. et stabilité des étoiles et des amas d'étoiles (ESEA)
Miglio, Andrea ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Montalban Iglesias, Josefa ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Dupret, Marc-Antoine ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Aerts, C.; Katholieke Universiteit Leuven, Departement Natuurkunde en Sterrenkunde, Instituut voor Sterrenkunde, Celestijnenlaan 200D, 3001 Leuven, Belgium
Language :
English
Title :
An asteroseismic study of the β cephei star θ ophiuchi : constraints on global stellar parameters and core overshooting
Aerts C., Marchenko S. V., Matthews J. M., 2006, ApJ, 642, 470
Aerts C., Thoul A., Daszyñska J., Scuflaire R., Waelkens C., Dupret M. A., Niemczura E., Noels A., 2003, Sci, 300, 1926
Aerts C. et al., 2004, A&A, 415, 241
Ausseloos M., Scuflaire R., Thoul A., Aerts C., 2004, MNRAS, 355, 352
Asplund M., Grevesse N., Sauval A. J., 2005, in Barnes T. G. III., Bash F. N., eds, ASP Conf. Ser. Vol. 336, Cosmic abundances as records of stellar evolution and nucleosynthesis. Astron. Soc. Pac., San Francisco, p. 25
Böhm-Vitense E., 1958, Z. Astrophys., 46, 108
Bourge P.-O., Alecian G., Thoul A., Scuflaire R., Théado S., 2006, Commun. Asteroseismol., 147, 105
Briquet M., Lefever K., Uytterhoeven K., Aerts C., 2005, MNRAS, 362, 619 (Paper II)
Caughlan G. R., Fowler W. A., 1988, At. Data Nucl. Data Tables, 40, 283
Cunha K., Hubeny I., Lanz T., 2006, ApJ, 647, L143
Daflon S., Cunha K., 2004, ApJ, 617, 1115
De Ridder J. et al., 2004, MNRAS, 351, 324
Deupree R. G., 2000, ApJ 543, 395
Dupret M.-A., 2001, A&A, 366, 166
Dupret M.-A., Thoul A., Scuflaire R., Daszyñska-Daszkiewicz J., Aerts C., Bourge P.-O., Waelkens C., Noels A., 2004, A&A, 415, 251
Ferguson J. W., Alexander D. R., Allard F., Barman T., Bodnarik J. G., Hauschildt P. H., Heffner-Wong A., Tamanai A., 2005, ApJ, 623, 585
Formicola A. et al., 2004, Phys. Lett. B, 591, 61
Grevesse N., Sauval A. J., 1998, Space Sci. Rev., 85, 161
Handler G., Shobbrook R. R., Mokgwetsi T., 2005, MNRAS, 362, 612 (Paper I)
Kaiser A., 2006, in Sternken C., Aerts C., eds, ASP Conf. Ser. Vol. 349 Astrophysics of Variable Stars. Astron. Soc. Pac., San Francisco, p. 257
Kurucz R. L., 1993, ATLAS9 Stellar Atmosphere Programs and 2 km s -1 grid. Kurucz CD-ROM No. 13. Smithsonian Astrophysical Observatory, Cambridge, Massachusetts, p. 13
Lynden-Bell D., Ostriker J. P., 1967, MNRAS, 136, 293
Mazumdar A., Briquet M., Desmet M., Aerts C., 2006, A&A, 459, 589
McAlister H., Mason B. D., Hartkopf W. I., Shara M. M., 1993, AJ, 106, 1639
Miglio A., Montalbán J., Dupret M.-A., 2007, MNRAS, 375, 21
Morel T., Butler K., Aerts C., Neiner C., Briquet M., 2006, A&A, 457, 651
Niemczura E., Daszynska-Daszkiewicz J., 2005, A&A, 433, 659
Pamyatnykh A. A., Handler G., Dziembowski W. A., 2004, MNRAS, 350, 1022
Puls J., Urbaneja M. A., Venero R., Repolust T., Springmann U., Jokuthy A., Mokiem M. R., 2005, A&A, 435, 669
Ribas I., Jordi C., Gimnez A., 2000, MNRAS, 318, 55
Rogers F. J., Nayfonov A., 2002, ApJ, 576, 1064
Scuflaire R., Théado S., Montalban J., Miglio A., Bourge P.-O., Godart M., Thoul A., Noels A., 2007a, Ap&SS, 322, in press
Scuflaire R., Montalban J., Théado S., Bourge P.-O., Miglio A., Godart M., Thoul A., Noels A., 2007b, Ap&SS, 322, in press
Seaton M. J., 2005, MNRAS, 362, L1
Smalley B., Dworetsky M. M., 1995, A&A, 293, 446
Soufi F., Goupil M.-J., Dziembowski W. A., 1998, A&A, 334, 911
Suárez J. C., 2002, PhD thesis, Observatoire de Paris
Talon S., Zahn J.-P., Maeder A., Meynet G., 1997, A&A, 322, 209
Thoul A., Bahcall J., Loeb A., 1994, ApJ, 421, 828