Asteroseismic analysis of Kepler target KIC 2837475

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 $δ_{\rm ov}$ 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 $δ_{\rm ov}$. Thus the ratio distributions are more sensitive to $δ_{\rm ov}$ 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 $1.2\lesssim$ $δ_{\rm ov}$ $\lesssim1.6$ for KIC 2837475.

Accepted for publication in MNRAS. 9 pages, 10 figures. The ratios $r_{01}$ and $r_{10}$ of KIC 2837475 exhibit an interesting behavior, which can be directly reproduced by stellar models. Adiabatic oscillation frequencies of the models can be downloaded from http://pan.baidu.com/s/1c00LPwk. arXiv admin note: text overlap with arXiv:1508.00955