论文标题
KIC 6951642：确认的开普勒$γ$ doradus- $δ$Δ$ scuti Star具有中间位置，以在可能的单层二进制系统中快速旋转
KIC 6951642: confirmed Kepler $γ$ Doradus-$δ$ Scuti star with intermediate to fast rotation in a possible single-lined binary system
论文作者
论文摘要
据报道，KIC 6951642是$γ$ doradus-doradus-$δ$Δ$ scuti的候选混合动力脉动，从开普勒任务的第一季度观察到。我们旨在研究KIC 6951642的脉动性质，并在光曲线中寻找旋转和/或活动的标志。我们对两个傅立叶光谱进行了迭代频率搜索，并在其中搜索了常规模式。我们应用光谱合成以确定大气恒星参数。由于据报道KIC 6951642属于光谱二进制系统，因此我们拟合了从光曲线得出的时间延迟，并与已发布的径向速度以及从已发布的新光谱获得的径向速度拟合，以改善第一轨的质量。随访光谱表明，KIC 6951642是可能的单层二进制中快速旋转的F0型星，$ \ sim $ 4.8 yr。在低频制度中，我们确定了0.721 D $^{ - 1} $的频率以及0.0087 D $^{ - 1} $。我们将第一个频率归因于恒星旋转，而第二个频率则归因于一个周期的恒星活动。我们还检测到$ G $模式，最强模式位于2.238 d $^{ - 1} $，以及三个不对称的多重模式（平均间距为0.675 $ \ pm $ 0.044 d $^{ - 1} $）。在高频制度中，我们检测到类型为$δ$ scuti的频率，最强模式位于13.96 d $^{ - 1} $，以及七个不对称的多重多重频率（平均间隔为0.665 $ \ pm $ $ 0.084 D $^$^{ - 1} $）。随后，我们确定了一些频率似乎是$ g $或$ p $模式的组合，而不是由于脉动引起的较高引用的频率之一。我们建议KIC 6951642适用于快速旋转的$γ$ dor- $δ$Δ$ sct混合恒星，具有$ g $和$ p $模式的各种旋转式拆分多重，并且还显示了持续的（可能）（可能的）星级活动的周期。
KIC 6951642 has been reported as a candidate hybrid pulsator of type-$γ$ Doradus-$δ$ Scuti from observations of the first quarters of the Kepler mission. We aim to investigate the pulsating nature of KIC 6951642 and to search for the signature of rotation and/or activity in the light curves. We performed an iterative frequency search of both Fourier spectra, and searched for regular patterns in them. We applied spectrum synthesis to determine the atmospheric stellar parameters. Since KIC 6951642 was reported to belong to a spectroscopic binary system, we fitted the time delays derived from the light curves with the radial velocities obtained from published as well as new spectra in an attempt to improve the quality of the first orbit. Follow-up spectroscopy showed that KIC 6951642 is a fast-rotating F0-type star in a possible single-lined binary with a period of $\sim$4.8 yr. In the low-frequency regime, we identified the frequencies of 0.721 d$^{-1}$ as well as of 0.0087 d$^{-1}$. We attribute the first frequency to stellar rotation and the second one to stellar activity with a cycle. We also detected $g$ modes, with the strongest mode located at 2.238 d$^{-1}$, as well as three asymmetric multiplets (with a mean spacing of 0.675$\pm$0.044 d$^{-1}$). In the high-frequency regime, we detected frequencies of type-$δ$ Scuti, with the strongest mode located at 13.96 d$^{-1}$, as well as seven asymmetric multiplets (with a mean spacing of 0.665$\pm$0.084 d$^{-1}$). We subsequently identified a few more frequencies that appear to be combinations of a $g$ or $p$ mode and one of the higher cited frequencies not due to pulsations. We propose that KIC 6951642 accommodates for a fast-rotating $γ$ Dor-$δ$ Sct hybrid star with various rotationally split multiplets of $g$ and $p$ modes and that it also displays a cycle lasting years of (possible) stellar activity.
