Asteroseismic analysis of Kepler target KIC 2837475

TL;DR

This study uses asteroseismic ratios to constrain the internal structure and overshooting parameter of star KIC 2837475, providing precise stellar properties and insights into core overshooting effects.

Contribution

It demonstrates that the ratios $r_{01}$ and $r_{10}$ are highly sensitive to the overshooting parameter, enabling strict constraints on stellar models and core overshooting.

Findings

Observed ratios increase with overshooting parameter.

Best-fit models suggest specific mass, radius, and age for KIC 2837475.

Ratios effectively constrain core overshooting extent.

Abstract

The ratios $r_{01}$ and $r_{10}$ of small to large separations of KIC 2837475 primarily exhibit an increase behavior in the observed frequency range. The calculations indicate that only the models with overshooting parameter $\delta_{\rm ov}$ between approximately 1.2 and 1.6 can reproduce the observed ratios $r_{01}$ and $r_{10}$ of KIC 2837475. The ratios $r_{01}$ and $r_{10}$ of the frequency separations of p-modes with inner turning points that are located in the overshooting region of convective core can exhibit an increase behavior. The frequencies of the modes that can reach the overshooting region decrease with the increase in $\delta_{\rm ov}$. Thus the ratio distributions are more sensitive to $\delta_{\rm ov}$ than to other parameters. The increase behavior of the KIC 2837475 ratios results from a direct effect of the overshooting of convective core. The characteristic of the ratios provides a strict constraint on stellar models. Observational constraints point to a star with $M=1.490\pm0.018$ $M_{\odot}$, $R=1.67\pm0.01$ $R_{\odot}$, age $=2.8\pm0.4$ Gyr, and $1.2\lesssim$ $\delta_{\rm ov}$ $\lesssim1.6$ for KIC 2837475.