Seismic modelling of the $\beta$Cep star HD\,180642 (V1449\,Aql)

Abstract

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.

10 pages, 2 Tables, 6 Figures. Accepted for publication in Astronomy and Astrophysics

References in corpus (12)

• Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars
• Ensemble Asteroseismology of Solar-Type Stars with the NASA Kepler Mission
• CLES, Code Liegeois d'Evolution Stellaire
• An asteroseismic study of the beta Cephei star theta Ophiuchi: constraints on global stellar parameters and core overshooting
• The Liege Oscillation Code
• Variability in the CoRoT photometry of three hot O-type stars. HD 46223, HD 46150 and HD 46966
• An asteroseismic study of the O9V star HD 46202 from CoRoT space-based photometry
• Solar-like oscillations in a massive star
• The excitation of solar-like oscillations in a delta Scuti star by efficient envelope convection
• Inter-comparison of the g-, f- and p-modes calculated using different oscillation codes for a given stellar model
• CoRoT high-precision photometry of the B0.5 IV star HD 51756
• The strong magnetic field of the large-amplitude beta Cephei pulsator V1449 Aql

Cited by in corpus (23)

• Gravito-inertial and pressure modes detected in the B3 IV CoRoT target HD 43317
• On the photometric detection of Internal Gravity Waves in upper main-sequence stars I. Methodology and application to CoRoT targets
• Multisite spectroscopic seismic study of the beta Cep star V2052 Oph: inhibition of mixing by its magnetic field
• The eccentric massive binary V380 Cyg: revised orbital elements and interpretation of the intrinsic variability of the primary component
• The surface nitrogen abundance of a massive star in relation to its oscillations, rotation, and magnetic field
• The Observational Signatures of Convectively Excited Internal Gravity Modes in Main Sequence Stars
• Pulsation among TESS A and B stars and the Maia variables
• Convective boundary mixing in main-sequence stars: theory and empirical constraints
• Short-term variability and mass loss in Be stars II. Physical taxonomy of photometric variability observed by the Kepler spacecraft
• Discovery of a magnetic field in the CoRoT hybrid B-type pulsator HD 43317
• A multisite photometric study of two unusual Beta Cep stars: the magnetic V2052 Oph and the massive rapid rotator V986 Oph
• Pulsating B-type stars in the open cluster NGC 884: frequencies, mode identification and asteroseismology
• New $\beta$ Cep pulsators discovered with K2 space photometry
• Detection of gravity modes in the massive binary V380 Cyg from Kepler spacebased photometry and high-resolution spectroscopy
• Asteroseismology of binary stars and a compilation of core overshoot and rotational frequency values of OB stars
• High-precision CoRoT space photometry and fundamental parameter determination of the B2.5V star HD 48977
• Age-dating the young open cluster UBC 1 with g-mode asteroseismology, gyrochronology, and isochrone fitting
• Backtracing the internal rotation history of the $\beta$ Cep star HD 129929
• Asteroseismology of $\beta$ Cephei stars: The stellar inferences tested in hare and hound exercises
• The ESO UVES/FEROS Large Programs of TESS OB pulsators. I. Global stellar parameters from high-resolution spectroscopy
• Chaos in large-amplitude pulsators: application to the beta Cep star HD180642
• Magnetic field studies of massive main sequence stars
• Probing high-mass stellar evolutionary models with binary stars