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An asteroseismic study of the β Cephei star θ Ophiuchi: constraints on global stellar parameters and core overshooting.

Authors :
Briquet, M.
Morel, T.
Thoul, A.
Scuflaire, R.
Miglio, A.
Montalbán, J.
Dupret, M.-A.
Aerts, C.
Source :
Monthly Notices of the Royal Astronomical Society; 11/11/2007, Vol. 381 Issue 4, p1482-1488, 7p, 7 Charts, 4 Graphs
Publication Year :
2007

Abstract

We present a seismic study of the β Cephei star θ Ophiuchi. Our analysis is based on the observation of one radial mode, one rotationally split triplet and three components of a rotationally split quintuplet for which the m values were well identified by spectroscopy. We identify the radial mode as fundamental, the triplet as p<subscript>1</subscript> and the quintuplet as g<subscript>1</subscript>. 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 and , 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 and central hydrogen abundance of θ Oph and to prove the occurrence of core overshooting . We also derive an equatorial rotation velocity of . Moreover, we show that the observed non-equidistance of the 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. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00358711
Volume :
381
Issue :
4
Database :
Complementary Index
Journal :
Monthly Notices of the Royal Astronomical Society
Publication Type :
Academic Journal
Accession number :
27301113
Full Text :
https://doi.org/10.1111/j.1365-2966.2007.12142.x