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The Eclipsing δ Scuti Star EPIC 245932119 SCI
  • 이재우;홍경수;Martti H. Kristiansen
  • 2019-01-01
  • ASTRONOMICAL JOURNAL 157 1 : 17-1~17-8
We present the physical properties of EPIC 245932119 (K p = +9.82) exhibiting both eclipses and pulsations from the K2 photometry. The binary modeling indicates that the eclipsing system is in detached or semi-detached configurations with a mass ratio of 0.283 or 0.245, respectively, and that its light-curve parameters are almost unaffected by pulsations. Multiple frequency analyses were performed for the light residuals in the outside-primary eclipsing phase after subtracting the binarity effects from the observed data. We detected 35 frequencies with signal-to-noise amplitude ratios larger than 4.0 in two regions of 0.62?6.28 day?1 and 19.36?24.07 day?1. Among these, it is possible that some high signals close to the Nyquist limit f Ny may be reflections of real pulsation frequencies (2${f}_{\mathrm{Ny}}-{f}_{i}$). All frequencies (f 8, f 9, f 14, f 18, f 24, f 32) in the lower frequency region are orbital harmonics, and three high frequencies (f 19, f 20, f 22) appear to be sidelobes split from the main frequency of f 1 = 22.77503 day?1. Most of them are thought to be alias effects caused by the orbital frequency. For the 26 other frequencies, the pulsation periods and pulsation constants are in the ranges of 0.041?0.052 days and 0.013?0.016 days, respectively. These values and the position in the Hertzsprung?Russell diagram reveal that the primary component is a δ Sct pulsator. The observational properties of EPIC 245932119 are in good agreement with those for eclipsing binaries with δ Sct-type pulsating components.