Seismic diagnostics of solar-like oscillating stars

Abstract

High precision and long-lasting Kepler data enabled us to estimate stellar properties with asteroseismology as an accurate tool. We performed asteroseismic analysis on six solar-like stars observed by the Kepler mission: KIC 6064910, KIC 6766513, KIC 7107778, KIC 10079226, KIC 10147635 and KIC 12069127. The extraction of seismic information includes two parts. First, we obtained two global asteroseismic parameters, mean large separation Δν and frequency of maximum power νmax, with autocorrelation function and collapsed autocorrelation function. Second, we extracted individual oscillation modes ν nl with low-l degree using a least-squares fit. Stellar grid models were built with Yale Rotating Stellar Evolution Code (YREC) to analyze stellar properties. They covered the range of M = 0.8 ∼ 1.8 M⊙ with a step of 0.02M⊙ and [Fe/H] = -0.3 ∼ 0.4 dex with a step of 0.02 and dex with a step of 0.1 dex. We used a Bayesian approach to estimate stellar fundamental parameters of the six stars, under the constraints of asteroseismic parameters (Δν, νmax) and non-asteroseismic parameters (Teff,[Fe/H] ). We discover that the six targets include five sub-giant stars with 1.2 ∼ 1.5 M⊙ and one main-sequence star with 1.2 ∼ 1.5M⊙, and with 1.08 M⊙ ages in the range of 3 ∼ 5 Gyr.