Mode identification and ensemble asteroseismology of 119 $\beta$ Cep stars detected by Gaia light curves and monitored by TESS

Abstract

The Gaia mission detected many new candidate $\beta$ Cephei ($\beta$ Cep) pulsators, whose variability classification has since been confirmed from Transiting Exoplanet Survey Satellite (TESS) space photometry of the nominal mission. We aim to analyse all currently available TESS data for these $\beta$ Cep pulsators, of which 145 were new discoveries, in order to exploit their asteroseismic potential. Although they are of critical importance to improve evolution models of massive stars, $\beta$ Cep stars are under-represented in the current space photometry revolution. We extracted light curves for 216 stars from TESS full-frame images and performed frequency analysis by means of pre-whitening. Based on Gaia Data Release 3, we deduced stellar properties and compared them to those of known $\beta$ Cep stars from the literature. We developed a methodology to identify the dominant pulsation modes of the $\beta$ Cep stars from the detection of rotationally-split multiplets and Gaia and TESS amplitude ratios. We used grid modelling to gain insights into the population of $\beta$ Cep stars. Combining TESS and Gaia, we successfully identified the mode degrees for 148 stars in our sample. We find the majority to have a dominant dipole non-radial mode. Many non-radial modes show splittings in their TESS frequency spectra, which we use to calculate their envelope rotation, spin parameter, and the level of differential envelope-to-surface rotation (upper limit of about 3). We also provide relative frequency asymmetries within the multiplets, ranging from -0.15 to 0.15 with most being positive. Based on grid modelling, we provide mass, convective core mass, and age distributions for 119 stars. Our study prepares for future detailed modelling based on individual frequencies of identified modes leading towards a better understanding of these massive pulsators. (abridged)

Resbumitted to A&A after taking into account all the comments from the referee

References in corpus (40)

• Array Programming with NumPy
• The Transiting Exoplanet Survey Satellite
• Painting a portrait of the Galactic disc with its stellar clusters
• Improving the open cluster census. II. An all-sky cluster catalogue with Gaia DR3
• The MiMeS survey of magnetism in massive stars: Magnetic analysis of the O-type stars
• Gaia Data Release 3: Astrophysical parameters inference system (Apsis) I -- methods and content overview
• Acoustic oscillations of rapidly rotating polytropic stars. II. Effects of the Coriolis and centrifugal accelerations
• Gaia Data Release 3: Apsis II -- Stellar Parameters
• An asteroseismic study of the beta Cephei star theta Ophiuchi: constraints on global stellar parameters and core overshooting
• Variability of OB stars from TESS southern Sectors 1-13 and high-resolution IACOB and OWN spectroscopy
• The two hybrid B-type pulsators: Nu Eridani and 12 Lacertae
• Diverse Variability of O and B Stars Revealed from 2-minute Cadence Light Curves in Sectors 1 and 2 of the TESS Mission: Selection of an Asteroseismic Sample
• The period-luminosity relation for delta Scuti stars using Gaia DR2 parallaxes
• Solar-like oscillations in a massive star
• New magnetic field measurements of beta Cephei stars and Slowly Pulsating B stars
• delta Ceti is not monoperiodic: seismic modeling of a beta Cephei star from MOST spacebased photometry
• Strong magnetic fields detected in the cores of 11 red giant stars using gravity-mode period spacings
• Magnetic signatures on mixed-mode frequencies. I. An axisymmetric fossil field inside the core of red giants
• Gaia Data Release 3: Pulsations in main sequence OBAF-type stars
• Asteroseismic inference of the near-core magnetic field strength in the main sequence B star HD 43317
• The effect of tides on near-core rotation: analysis of 35 Kepler $\gamma$ Doradus stars in eclipsing and spectroscopic binaries
• Beta Cephei stars in the ASAS-3 data. II. 103 new Beta Cephei stars and a discussion of low-frequency modes
• Near-degeneracy effects on the frequencies of rotationally-split mixed modes in red giants
• The CubeSpec space mission. I. Asteroseismology of massive stars from time series optical spectroscopy: science requirements and target list prioritisation
• High-mass pulsators in eclipsing binaries observed using TESS
• Recipes for bolometric corrections and Gaia luminosities of B-type stars: Application to an asteroseismic sample
• Detection of nonlinear resonances among gravity modes of slowly pulsating B stars: results from five iterative prewhitening strategies
• Confronting sparse Gaia DR3 photometry with TESS for a sample of around 60,000 OBAF-type pulsators
• Detection of period-spacing patterns due to the gravity modes of rotating dwarfs in the TESS southern continuous viewing zone
• Astrophysical properties of 15062 Gaia DR3 gravity-mode pulsators: pulsation amplitudes, rotation, and spectral line broadening
• Asymmetries of frequency splittings of dipolar mixed modes: a window on the topology of deep magnetic fields
• The $\beta$ Cep/SPB star 12 Lacertae: extended mode identification and complex seismic modelling
• Modeling overcontact binaries, I. The effect of tidal deformation
• Modeling contact binaries, II. The effect of energy transfer
• Pulsating B stars in the Scorpius-Centaurus Association with TESS
• Ensemble asteroseismology of pulsating B-type stars in NGC 6910
• Observational properties of 155 O- and B-type massive pulsating stars
• Asteroseismology of $\beta$ Cephei stars: The stellar inferences tested in hare and hound exercises
• Identifying 850 delta Scuti pulsators in a narrow Gaia colour range with TESS 10-minute full-frame images
• Observational Properties of 155 $\beta$ Cephei pulsating variable stars

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