Estimates of (convective core) masses, radii, and relative ages for ∼14 000 Gaia-discovered gravity-mode pulsators monitored by TESS

¹ IRAP, Université de Toulouse, CNRS, UPS, CNES, 14 Avenue Édouard Belin, F-31400 Toulouse, France
² Institute of Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium
³ Université Paris-Saclay, Université de Paris, Sorbonne Paris Cité, CEA, CNRS, AIM, 91191 Gif-sur-Yvette, France
⁴ Department of Astrophysics, IMAPP, Radboud University Nijmegen, PO Box 9010 6500 GL Nijmegen, The Netherlands
⁵ Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
⁶ Institute for Astronomy, University of Hawai’i, Honolulu, HI, 96822 USA

^⋆ Corresponding authors; joey.mombarg@cea.fr; conny.aerts@kuleuven.be

Received: 25 July 2024
Accepted: 4 October 2024

Abstract

Context. Gravito-inertial asteroseismology saw its birth from the 4-year-long light curves of rotating main-sequence stars assembled by the Kepler space telescope. High-precision measurements of internal rotation and mixing are available for about 600 stars of intermediate mass so far that are used to challenge the state-of-the-art stellar structure and evolution models.

Aims. Our aim is to prepare for future large ensemble modelling of gravity-mode pulsators by relying on a new sample of such stars recently discovered from the third Data Release of the Gaia space mission and confirmed by space photometry from the TESS mission. This sample of potential asteroseismic targets is about 23 times larger than the Kepler sample.

Methods. We use the effective temperature and luminosity inferred from Gaia to deduce evolutionary masses, convective core masses, radii, and ages for ∼14 000 gravity-mode pulsators classified as such from their nominal TESS light curves. We do so by constructing two dedicated grids of evolutionary models for rotating stars with input physics from the asteroseismic calibrations of Keplerγ Dor pulsators. These two grids consider the distribution of initial rotation velocities at the zero-age main sequence deduced from gravito-inertial asteroseismology, for two extreme values found for the metallicity of γ Dor stars deduced from spectroscopy ([M/H]=0.0 and −0.5).

Results. We find the new gravity-mode pulsators to cover an extended observational instability region covering masses from about 1.3 M_⊙ to about 9 M_⊙. We provide their mass-luminosity and mass-radius relations, as well as convective core masses. Our results suggest that oscillations excited by the opacity mechanism occur uninterruptedly for the mass range above about 2 M_⊙, where stars have a radiative envelope aside from thin convection zones in their excitation layers.

Conclusions. Our evolutionary parameters for the sample of Gaia-discovered gravity-mode pulsators with confirmed modes by TESS offer a fruitful starting point for future TESS ensemble asteroseismology once a sufficient number of modes is identified in terms of the geometrical wave numbers and overtone for each of the pulsators.