KIC 10975348: A Double-mode or Triple-mode High-amplitude δ Scuti Star?
KIC 10975348: A Double-mode or Triple-mode High-amplitude δ Scuti Star?
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DOI：
10.3847/1538-3881/abcb8b
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
Tao Yang;Xiao-Ya Sun;Z. Zuo;H. Liu
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作者：
Tao Yang;Xiao-Ya Sun;Z. Zuo;H. Liu
在本文中，我们使用开普勒任务提供的光度数据分析了 KIC 10975348 的光变化。与大多数经过充分研究的盾牌座 δ 星相比，这颗恒星异常微弱（Kp = 18.6 星等）。对短节奏数据（即 Q14、Q15 和 Q16，跨度 220 天）的傅里叶分析表明，变化主要由频率为 F0 = 10.231899 day−1 的最强模式主导，这与 RATS-Kepler 获得的结果一致。另外两个独立模态 F1 (=13.4988 day−1) 和 F2 (=19.0002 day−1) 是新检测到的，其幅度比 F0 小两个数量级。我们注意到，这颗恒星首次被鉴定为高振幅 δ Sct (HADS) 星，振幅约为 0.7 星等，较低的 F0/F1 = 0.758 比率表明它可能是一颗富金属变星。频率 F2 可能是第三泛音模式，表明该目标可能是一颗新的径向三模式 HADS 恒星。我们利用新确定的1018个最大光次进行O-C分析，推导出星历公式Tmax = 2456170.241912(0)+0.097734(1)×E。从O-C图可以看出，KIC 10975348的脉动周期似乎没有明显变化，这与大多数HADS恒星形成鲜明对比。造成这种情况的可能原因可能是由于当前观测的时间跨度较短。为了验证其可能的周期变化，需要在未来进行更长时间跨度的太空定期观测。
In this paper, we analyze the light variations of KIC 10975348 using photometric data delivered from the Kepler mission. This star is exceptionally faint (Kp = 18.6 mag) compared to most well-studied δ Scuti stars. The Fourier analysis of the short-cadence data (i.e., Q14, Q15, and Q16, spanning 220 days) reveals that the variations are dominated by the strongest mode with a frequency of F0 = 10.231899 day−1, which is compatible with that obtained from RATS–Kepler. The other two independent modes with F1 (=13.4988 day−1) and F2 (=19.0002 day−1) are newly detected and have amplitudes two orders of magnitude smaller than F0. We note that, for the first time, this star is identified to be a high-amplitude δ Sct (HADS) star with an amplitude of about 0.7 mag, and the lower ratio of F0/F1 = 0.758 suggests that it might be a metal-rich variable star. The frequency F2 may be a third overtone mode, suggesting that this target might be a new radial triple-mode HADS star. We perform an O − C analysis using 1018 newly determined times of maximum light and derive an ephemeris formula of Tmax = 2456170.241912(0)+0.097734(1) × E. The O − C diagram shows that the pulsation period of KIC 10975348 seems to show no obvious change, which is in contrast to that of the majority of HADS stars. The possible cause of that may be due to the current short time span of the observations. To verify its possible period variations, regular observation from space with a longer time span in the future is needed.