Seismic modeling of a very young SPB star -- KIC8264293

Abstract

KIC8264293 is a fast rotating B-type pulsator observed by Kepler satellite. Its photometric variability is mainly due to pulsations in high-order g modes. Besides, we detected a weak H$\alpha$ emission. Thus, the second source of variability is the fluctuation in a disk around the star. The pulsational spectrum of KIC8264293 reveals a frequency grouping and period spacing pattern. Here, we present the thorough seismic analysis of the star based on these features. Taking into account the position of the star in the HR diagram and fitting the 14 frequencies that form the period spacing we constrain the internal structure of the star. We conclude that the star barely left the ZAMS and the best seismic model has $M=3.54{\mathrm{M}}_{\odot }$, $V_{\mathrm{rot}}=248{\mathrm{km}\mathrm{s}}^{-1}$ and $Z=0.0112$. We found the upper limit on the mixing at the edge of the convective core, with the overshooting parameter up to $f_{\mathrm{ov}}=0.03$. On the other hand, we were not able to constrain the envelope mixing for the star. To excite the modes in the observed frequency range, we had to modify the opacity data. Our best seismic model with an opacity increase by 100% at the "nickel" bump $\log T=5.46$ explains the whole instability. KIC8264293 is the unique, very young star pulsating in high-order g modes with the Be feature. However, it is not obvious whether the source of this circumstellar matter is the ejection of mass from the underlying star or whether the star has retained its protostellar disk.

arXiv commentAccepted for publication in Monthly Notices of the Royal Astronomical Society Main Journal

References in corpus (52)

• The chemical composition of the Sun
• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• Low Temperature Opacities
• A 3D Dust Map Based on Gaia, Pan-STARRS 1 and 2MASS
• Shell-model calculations of stellar weak interaction rates: II. Weak rates for nuclei in the mass range A=45-65 in supernovae environment
• Approximate input physics for stellar modelling
• Classical Be Stars: Rapidly Rotating B Stars with Viscous Keplerian Decretion Disks
• Updated Electron-Conduction Opacities: The Impact on Low-Mass Stellar Models
• Present-day cosmic abundances. A comprehensive study of nearby early B-type stars and implications for stellar and Galactic evolution and interstellar dust models
• Thermodynamic functions of dense plasmas: analytic approximations for astrophysical applications
• A New Generation of Los Alamos Opacity Tables
• Catalog of Galactic Beta Cephei Stars
• Tight asteroseismic constraints on core overshooting and diffusive mixing in the slowly rotating pulsating B8.3V star KIC 10526294
• Asteroseismology of the Beta Cephei star Nu Eridani: Interpretation and applications of the oscillation spectrum
• Sub-Inertial Gravity Modes in the B8V Star KIC 7760680 Reveal Moderate Core Overshooting and Low Vertical Diffusive Mixing
• Internal mixing of rotating stars inferred from dipole gravity modes
• Signatures of internal rotation discovered in the Kepler data of five slowly pulsating B stars
• The IACOB project: III. New observational clues to understand macroturbulent broadening in massive O- and B-type stars
• Kepler observations of variability in B-type stars
• Pulsation frequency distribution in Delta Scuti stars
• Asteroseismology of the Beta Cephei star 12 (DD) Lacertae: photometric observations, pulsational frequency analysis and mode identification
• The internal rotation profile of the B-type star KIC10526294 from frequency inversion of its dipole gravity modes and statistical model comparison
• Open Clusters as Galactic Disk Tracers: I. Project Motivation, Cluster Membership and Bulk Three-Dimensional Kinematics
• Short-term variability and mass loss in Be stars I. BRITE satellite photometry of $\eta$ and $\mu$ Centauri
• OP data on CD for mean opacities and radiative accelerations
• KIC 10526294: a slowly rotating B star with rotationally split, quasi-equally spaced gravity modes
• KIC 3240411 - the hottest known SPB star with the asymptotic g-mode period spacing
• Asteroseismic fingerprints of rotation and mixing in the slowly pulsating B8 V star KIC 7760680
• Asteroseismology of the Beta Cephei star Nu Eridani -- IV. The 2003-4 multisite photometric campaign and the combined 2002-4 data
• Testing the effects of opacity and the chemical mixture on the excitation of pulsations in B stars of the Magellanic Clouds
• Fundamental parameters for 45 open clusters with Gaia DR2, an improved extinction correction and a metallicity gradient prior
• On the use of the Fourier Transform to determine the projected rotational velocity of line-profile variable B stars
• Domains of pulsational instability of low-frequency modes in rotating upper main-sequence stars
• Interpretation of the BRITE oscillation data of the hybrid pulsator $\nu$ Eridani: a call for the modification of stellar opacities
• Variability of newly identified B-type stars observed by Kepler
• The CoRoT B-type binary HD50230: a prototypical hybrid pulsator with g-mode period and p-mode frequency spacings
• Excitation and visibility of slow modes in rotating B-type stars
• Transport of angular momentum by stochastically excited waves as an explanation for the outburst of the rapidly rotating Be star HD49330
• Outbursts and Disk Variability in Be Stars
• TESS observations of Be stars: a new interpretation
• A comprehensive study of the open cluster NGC 6866
• Seismic modelling of early B-type pulsators observed by BRITE: I. $\theta$ Ophiuchi
• The $\beta$ Cep/SPB star 12 Lacertae: extended mode identification and complex seismic modelling
• Ensemble asteroseismology of pulsating B-type stars in NGC 6910
• Seismic modelling of the rotating, slowly pulsating B-type star HD 21071
• Stellar Parameters for Pulsating B Star Candidates in the Kepler Field
• Inference for Stellar Opacities from Seismic Studies of the Hybrid $\beta$ Cep/SPB pulsators
• Deciphering the period spacing pattern in the oscillation spectrum of the SPB star KIC 7760680

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• Internal rotation and buoyancy travel time of 60 gamma Doradus stars from uninterrupted TESS light curves spanning 352 days
• Calibrating angular momentum transport in intermediate-mass stars from gravity-mode asteroseismology
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• Analysis of high-resolution FEROS spectroscopy for a sample of variable B-type stars assembled from TESS photometry
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• The ESO UVES/FEROS Large Programs of TESS OB pulsators. I. Global stellar parameters from high-resolution spectroscopy
• Non-linear Three-mode Coupling of Gravity Modes in Rotating Slowly Pulsating B Stars: Stationary Solutions and Modeling Potential
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