The $\beta$ Cep/SPB star 12 Lacertae: extended mode identification and complex seismic modelling

Abstract

Results of mode identification and seismic modelling of the $\beta$ Cep/SBP star 12 Lacertae are presented. Using data on the multi-colour photometry and radial velocity variations, we determine or constrain the mode degree, $\ell$, for all pulsational frequencies. Including the effects of rotation, we show that the dominant frequency, ${\nu }_1$, is most likely a pure $\ell =1$ mode and the low frequency, ${\nu }_A$, is a dipole retrograde mode. We construct a set of seismic models which fit two pulsational frequencies corresponding to the modes $\ell =0,$ p${}_1$ and $\ell =1,$ g${}_1$ and reproduce also the complex amplitude of the bolometric flux variations, $f$, for both frequencies simultaneously. Some of these seismic models reproduce also the frequency ${\nu }_A$, as a mode $\ell =1,$ g${}_{13}$ or g${}_{14}$, and its empirical values of $f$. Moreover, it was possible to find a model fitting the six 12 Lac frequencies (the first five and ${\nu }_A$), only if the rotational splitting was calculated for a velocity of $V_{\mathrm{rot}}\approx 75$ km/s. In the next step, we check the effects of model atmospheres, opacity data, chemical mixture and opacity enhancement. Our results show that the OP tables are preferred and an increase of opacities in the $Z-$bump spoils the concordance of the empirical and theoretical values of $f$.

arXiv comment13 pages, 10 figures, published in MNRAS

References in corpus (23)

• The chemical composition of the Sun
• Low Temperature Opacities
• Kepler Mission Design, Realized Photometric Performance, and Early Science
• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• Asteroseismology of the Beta Cephei star Nu Eridani: Interpretation and applications of the oscillation spectrum
• Abundance analysis of prime B-type targets for asteroseismology I. Nitrogen excess in slowly-rotating beta Cephei stars
• Photometric amplitudes and phases of nonradial oscillation in rotating stars
• The two hybrid B-type pulsators: Nu Eridani and 12 Lacertae
• Asteroseismology of the Beta Cephei star 12 (DD) Lacertae: photometric observations, pulsational frequency analysis and mode identification
• Asteroseismology of the Beta Cephei star Nu Eridani: photometric observations and pulsational frequency analysis
• Constraints on stellar convection from multi-colour photometry of Delta Scuti stars
• Asteroseismology of the Beta Cephei star Nu Eridani -- IV. The 2003-4 multisite photometric campaign and the combined 2002-4 data
• An asteroseismic study of the beta Cephei star 12 Lacertae: multisite spectroscopic observations, mode identification and seismic modelling
• Confirmation of simultaneous p and g mode excitation in HD 8801 and Gamma Peg from time-resolved multicolour photometry of six candidate "hybrid" pulsators
• Asteroseismology of hybrid pulsators made possible: simultaneous MOST space photometry and ground-based spectroscopy of Gamma Peg
• Molecular Line Observations of Infrared Dark Clouds II: Physical Conditions
• Metallicities of the beta Cephei stars from low-resolution ultraviolet spectra
• Constraints on parameters of B-type pulsators from combined multicolour photometry and radial velocity data. I. $\beta$ Cephei stars
• Complex asteroseismology of the $\beta$ Cep/SPB pulsator $\nu$ Eridani: constraints on opacities
• Constraints on opacities from complex asteroseismology of B-type pulsators: the $\beta$ Cephei star $\theta$ Ophiuchi
• Effect of NLTE model atmospheres on photometric amplitudes and phases of early B-type pulsating stars
• Instability strips of main sequence B stars: a parametric study of iron enhancement
• Complex asteroseismology of the hybrid B-type pulsator $\gamma$ Pegasi: a test of stellar opacities

Cited by in corpus (12)

• A New Generation of Los Alamos Opacity Tables
• Photometric detection of internal gravity waves in upper main-sequence stars. II. Combined TESS photometry and high-resolution spectroscopy
• The CubeSpec space mission. I. Asteroseismology of massive stars from time series optical spectroscopy: science requirements and target list prioritisation
• Seismic modeling of a very young SPB star -- KIC8264293
• Photometric detection of internal gravity waves in upper main-sequence stars. III. Comparison of amplitude spectrum fitting and Gaussian process regression using celerite2
• Characterization of the variability in the O+B eclipsing binary HD 165246
• Mode identification and ensemble asteroseismology of 119 $\beta$ Cep stars detected by Gaia light curves and monitored by TESS
• Asteroseismology of $\beta$ Cephei stars: The stellar inferences tested in hare and hound exercises
• Helioseismic inference of the solar radiative opacity
• Revising the evolutionary stage of HD 163899: the effects of convective overshooting and rotation
• Discovery and Characterization of a Rare Magnetic Hybrid $\beta$ Cephei Slowly Pulsating B-type Star in an Eclipsing Binary in the Young Open Cluster NGC 6193
• Testing microphysics data