Asteroseismic analysis of Kepler target KIC 2837475

Abstract

The ratios r01 and r10 of small-to-large separations of KIC 2837475 primarily exhibit an increasing behaviour in the observed frequency range. The calculations indicate that only the models with overshooting parameter δov between approximately 1.2 and 1.6 can reproduce the observed ratios r01 and r10 of KIC 2837475. The ratios r01 and r10 of the frequency separations of p modes with inner turning points that are located in the overshooting region of convective core can exhibit an increasing behaviour. The frequencies of the modes that can reach the overshooting region decrease with the increase in δov. Thus, the ratio distributions are more sensitive to δov than to other parameters. The increasing behaviour 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 ± 0.018 M⊙, R = 1.67 ± 0.01 R⊙, age =2.8 ± 0.4 Gyr, and 1.2 ≲ δov ≲ 1.6 for KIC 2837475.