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

TL;DR

This study estimates fundamental stellar parameters for approximately 14,000 Gaia-discovered g-mode pulsators using TESS data, expanding the sample size and providing new insights into their internal structures and evolutionary states.

Contribution

It introduces a large new sample of g-mode pulsators with derived stellar parameters, based on models calibrated with Kepler data, enabling future ensemble asteroseismology.

Findings

Extended the observational instability region to 1.3-9Msun.

Provided mass-luminosity and mass-radius relations for the sample.

Indicated continuous excitation of oscillations above 2Msun.

Abstract

Gravito-inertial asteroseismology saw its birth from the 4-years 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. Our aim is to prepare for future large ensemble modelling of gravity (g)-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. We use the effective temperature and luminosity inferred from Gaia to deduce evolutionary masses, convective core masses, radii, and ages for ~14,000 g-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 Kepler $\gamma$ Dor pulsators. We find the new g-mode pulsators to cover an extended observational instability region covering masses from about 1.3 to 9Msun. 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 2Msun, where stars have a radiative envelope aside from thin convection zones in their excitation layers. Our evolutionary parameters for the sample of Gaia-discovered g-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.