KIC 12602250: A Low-amplitude Double-mode Delta Scuti Star with Amplitude Modulation

Abstract

We report a detailed light-curve analysis of the Kepler target Kepler Input Catalog (KIC) 12602250. The results show that KIC 12602250 is a low-amplitude radial double-mode δ- Scuti star with amplitude modulation. The Fourier analysis of the long cadence data (i.e., Q0—Q17, spanning 1471 days) reveals that the variations of the light curve are dominated by the strongest mode with frequency F 0 = 11.6141 d −1 , suggesting that KIC 12602250 is a δ -Scuti star. The other independent mode F 1 = 14.9741 d −1 is newly detected. The amplitude of the light variations of KIC 12602250 is ∼0.06 mag, which indicates that this is a low-amplitude δ -Scuti star; but the ratio of F 0/ F 1 is estimated as 0.7756, which is typical of HADS, and a slow amplitude growth is detected in F 1 and f 3 , which could be due to stellar evolution, suggesting that KIC 12602250 could be a post-main-sequence δ Scuti that is crossing the instability strip for the first time.