Mode identification and period fitting in six pulsating hot subdwarfs

Abstract

We report the results of our analysis of six gravity-mode pulsating hot subdwarf stars observed in the short cadence mode by Transiting Exoplanet Survey Satellite. We detected at least 10 pulsation periods in each star, searched for multiplets, and used an asymptotic period spacing to identify modes. We used a grid of evolutionary and pulsation models calculated with the MESA and GYRE, along with spectroscopic parameters and modal degree identification, to derive the physical properties of the stars. We checked the relation between the helium content and pulsations and found that no pulsator exists among the extremely helium-rich hot subdwarfs, while the number of detected pulsators in other helium groups increases as the helium content decreases. We found p- and g-mode hot subdwarfs pulsators in all Galactic populations.