论文标题
向前建模同伴的轨道,从光线旅行时间变化到脉动恒星
Forward modeling the orbits of companions to pulsating stars from their light travel time variations
论文作者
论文摘要
脉动恒星和轨道伴侣之间的相互重力导致了通往地球的星光的路径长度的时间依赖性变化。这些变化可用于相干脉动的恒星,例如δScuti变量,以限制其伴侣的质量和轨道。观察δScuti恒星的这些变化以前已依赖于光曲线的细分并测量同等大小的细分中的平均脉动阶段,从而导致附近附近的下采样不足。我们引入了一种新方法,该方法同时将每个样品转向光曲线中,并表明该方法在当前的灵敏度限制下有所改善,尤其是在高度偏心和短期二进制文件的情况下。我们发现,这种方法足够敏感,可以在理想条件下观察δScuti恒星周围的木星质量行星,并在Subdwarf B Star KIC 7668647中使用重力模式搏动在没有径向速度数据的情况下检测其伴侣。我们进一步提供了稳定的检测极限,这是脉动模式的SNR的函数,并确定典型的开普勒δscuti的最小可检测光行进时间幅度约为2 s。这种新方法显着增强了轻型旅行时间变化在检测使用脉动组件的短期二进制室以及脉动A型系外行星宿主星的应用中,尤其是作为消除假阳性的工具。
Mutual gravitation between a pulsating star and an orbital companion leads to a time-dependent variation in path length for starlight traveling to Earth. These variations can be used for coherently pulsating stars, such as the δ Scuti variables, to constrain the masses and orbits of their companions. Observing these variations for δ Scuti stars has previously relied on subdividing the light curve and measuring the average pulsation phase in equally sized subdivisions, which leads to under-sampling near periapsis. We introduce a new approach that simultaneously forward-models each sample in the light curve and show that this method improves upon current sensitivity limits - especially in the case of highly eccentric and short-period binaries. We find that this approach is sensitive enough to observe Jupiter mass planets around δ Scuti stars under ideal conditions, and use gravity-mode pulsations in the subdwarf B star KIC 7668647 to detect its companion without radial velocity data. We further provide robust detection limits as a function of the SNR of the pulsation mode and determine that the minimum detectable light travel time amplitude for a typical Kepler δ Scuti is around 2 s. This new method significantly enhances the application of light travel time variations to detecting short period binaries with pulsating components, and pulsating A-type exoplanet host stars, especially as a tool for eliminating false positives.