A comparison of the dynamical and model-derived parameters of the pulsating eclipsing binary KIC9850387

TL;DR

This study combines evolutionary, asteroseismic, and dynamical modeling to analyze the interior mixing and properties of the pulsating eclipsing binary KIC9850387, revealing high interior mixing levels and the importance of homogeneous analysis methods.

Contribution

It introduces a comprehensive approach integrating multiple modeling techniques to constrain the interior properties of a pulsating eclipsing binary, highlighting the need for homogeneous analyses.

Findings

System consists of two main-sequence stars at 1.2 Gyr.

Asteroseismic modeling yields stronger interior constraints than evolutionary modeling.

Evidence of high interior mixing and surface effects in the pulsating binary.

Abstract

We aim to unravel the interior mixing profile of the pulsating eclipsing binary KIC9850387 by comparing its dynamical parameters and the parameters derived through a combination of evolutionary and asteroseismic modelling. We created a grid of stellar evolutionary models using the stellar evolutionary code \textsc{mesa} and performed an isochrone-cloud (isocloud) based evolutionary modelling of the system. We then generated a grid of pulsational models using the stellar pulsation code \textsc{gyre} based on the age constraints from the evolutionary modelling. Finally, we performed asteroseismic modelling of the observed $\ell=1$ and $\ell=2$ period-spacing patterns, utilising different combinations of observational constraints, merit functions, and asteroseismic observables to obtain strong constraints on the interior properties of the primary star. Through a combination of asteroseismic modelling and dynamical constraints, we found that the system comprises two main-sequence components at an age of $1.2\pm0.1$ Gyr. We also observed that asteroseismic modelling provided stronger constraints on the interior properties than evolutionary modelling. Overall, we found high levels of interior mixing and posited that this is a result of intrinsic non-tidal mixing mechanisms due to a similar observed behaviour in single stars. We investigated the high-frequency regime of KIC9850387 and found evidence of the surface effect as well as rotational splitting in the form of a prograde-retrograde dipole g$_{1}$ mode doublet with a missing zonal mode. We find that the dynamical parameters and the parameters extracted from the asteroseismic modelling of period-spacing patterns are only barely compliant, reinforcing the need for homogeneous analyses of samples of pulsating eclipsing binaries that aim to calibrating interior mixing profiles.