KIC 5197256: an eclipsing binary containing a <i>δ</i> Scuti variable star

Abstract This paper reports analysis of an eclipsing binary system KIC 5197256 with a δ Sct variable component. Utilizing light-curve modeling, several stellar parameters are derived, e.g., temperature, mass, and mass ratio. The O – C diagram is a straight line with a negative slope which means that its period is almost constant for about 2 yr. Frequency analyses are performed for the residual light curve after subtracting the binary variations. The frequency spectrum reveals that one component star is a δ Scuti variable. Large frequency separation is cross-identified with the histogram graph and the Fourier transform method. Based on the large separation and density relationship, the mean density of the δ Sct component is estimated to be 0.05 g⋅cm −3 . Five frequencies with the same frequency spacing in the range of 25 d −1 – 34 d −1 are detected. Statistically, the pulsation amplitudes of δ Sct stars increase with decreasing of rotations, so we propose that KIC 5197256 might have a relatively large rotational velocity, and the frequency f 10 might be the rotation frequency.

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