2007/06/22 by M. Briquet, T. Morel, Anne Thoul +8
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics and Star Formation Studies #High-pressure geophysics and materials #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2007.12142.x
Accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journal on 2007-06-21, 8 pages, 4 figures
arxiv created 2007/06/22 · openalex publication_date 2007/10/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
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 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 p1 and the quintuplet as g1. 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∈[0.71, 0.7211] and Z∈[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⊙) and central hydrogen abundance (Xc= 0.38 ± 0.02) of θ Oph and to prove the occurrence of core overshooting (αov= 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.