Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2011-09-04
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
10 pages, 2 Tables, 6 Figures. Accepted for publication in Astronomy and Astrophysics
Scientific paper
We present modelling of the $\beta\,$Cep star HD\,180642 based on its observational properties deduced from CoRoT and ground-based photometry as well as from time-resolved spectroscopy. We investigate whether present-day state-of-the-art models are able to explain the full seismic behaviour of this star, which has extended observational constraints for this type of pulsator. We constructed a dedicated database of stellar models and their oscillation modes tuned to fit the dominant radial mode frequency of HD\,180642, by means of varying the hydrogen content, metallicity, mass, age, and core overshooting parameter. We compared the seismic properties of these models with those observed. We find models that are able to explain the numerous observed oscillation properties of the star, for a narrow range in mass of 11.4--11.8\,M$_\odot$ and no or very mild overshooting (with up to 0.05 local pressure scale heights), except for an excitation problem of the $\ell=3$, p$_1$ mode. We deduce a rotation period of about 13\,d, which is fully compatible with recent magnetic field measurements. The seismic models do not support the earlier claim of solar-like oscillations in the star. We instead ascribe the power excess at high frequency to non-linear resonant mode coupling between the high-amplitude radial fundamental mode and several of the low-order pressure modes. We report a discrepancy between the seismic and spectroscopic gravity at the $2.5\sigma$ level.
Aerts Christine
Briquet Maryline
Degroote Pieter
Hoolst Tim Van
Thoul Anne A.
No associations
LandOfFree
Seismic modelling of the $β\,$Cep star HD\,180642 (V1449\,Aql) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Seismic modelling of the $β\,$Cep star HD\,180642 (V1449\,Aql), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seismic modelling of the $β\,$Cep star HD\,180642 (V1449\,Aql) will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-109114