Asteroseismic modelling of the two F-type hybrid pulsators KIC10080943A and KIC10080943B

TL;DR

This paper models the internal structure of a binary star system with hybrid pulsators using seismic data and stellar evolution codes, constraining core overshooting and rotation effects to match observed pulsation patterns.

Contribution

It introduces a detailed seismic modeling approach for binary hybrid pulsators, incorporating rotation and mixing effects to better understand stellar interior physics.

Findings

Core overshooting and mixing are well constrained by the equal-age condition.

Best models suggest slightly lower masses than binary estimates due to g-mode period spacing.

Traditional approximation improves pulsation modeling by accounting for Coriolis effects.

Abstract

Pulsating binary stars are ideal targets for testing the theory of stellar structure and evolution. Fundamental parameters can be derived to high precision from binary modelling and provide crucial constraints for seismic modelling. High-order gravity modes are sensitive to the conditions near the convective core and therefore allow for a determination of parameters describing interior physics, especially the convective-core overshooting parameter. KIC\,10080943 is a binary system that contains two gravity- and pressure-mode hybrid pulsators. A detailed observational study has provided fundamental and seismic parameters for both components. We aim to find a model that is able to predict the observed g-mode period spacings and stellar parameters of both components of KIC 10080943. By calculating model grids with the stellar evolution code MESA and the seismic code GYRE, we can compare theoretical properties to the observed mean period spacing and position in the Hertzsprung-Russell diagram. The masses of our best models are somewhat below the values estimated from binarity, which is a consequence of the low observed mean g-mode period spacing. We find that the amount of core overshooting and diffusive mixing can be well constrained by the equal-age requirement for the two stars, however, we find no significant difference for different shapes of core overshooting. The measured rotation rates are within the limit of validity for the first-order perturbation approximation. We can find a good fit by using the traditional approximation for the pulsations, when taking slightly younger models with a higher asymptotic period spacing. This is because the zonal modes experience a slight shift due to the Coriolis force, which the first-order perturbation approximation ignores.