标题： 频率调制技术应用于脉动δSct-γDor食双星KIC 8569819的验证 显示英文标题

标题： Validation of the Frequency Modulation technique applied to the pulsating delta Sct - gamma Dor eclipsing binary star KIC 8569819

摘要： KIC 8569819 是一颗食双星，主星为早期F型，次星为G型，轨道周期为20.85天且具有偏心率。 主星是一种δ Scuti - γ Dor型变星，在p模式和g模式下均发生脉动。 利用开普勒任务四年的测光数据，我们独立地用传统方法通过建模代码PHOEBE模拟了光曲线，并使用新的频率调制（FM）技术研究了轨道特性。 我们证明这两种方法都提供了相同的轨道周期、偏心率和近拱点角，从而验证了FM技术的有效性。 在p模式脉动的振幅谱中，我们还发现了一个与系统内第三天体一致的FM信号，即一颗质量较低的M矮星，它以861天的周期绕主星对运行。 然而，掩食并未显示出时间变化，这表明FM信号是脉动频率内在变化的结果，从而提供了一个警示故事。 我们的分析展示了FM技术在{\it 开普勒}数据中的潜力，并讨论了即使没有凌日现象且缺乏光谱视向速度曲线的情况下，利用开普勒数据探测A型和F型恒星周围的行星和褐矮星的可能性。 这为寻找围绕比传统方法更难探测的较热恒星的行星开辟了可能性。 显示英文摘要

摘要： KIC 8569819 is an eclipsing binary star with an early F primary and G secondary in a 20.85-d eccentric orbit. The primary is a delta Sct - gamma Dor star pulsating in both p modes and g modes. Using 4 years of Kepler Mission photometric data we independently model the light curve using the traditional technique with the modelling code PHOEBE, and we study the orbital characteristics using the new frequency modulation (FM) technique. We show that both methods provide the equivalent orbital period, eccentricity and argument of periastron, thus illustrating and validating the FM technique. In the amplitude spectrum of the p-mode pulsations we also discovered an FM signal compatible with a third body in the system, a low mass M dwarf in an 861-d orbit around the primary pair. However, the eclipses show no timing variations, indicating that the FM signal is a consequence of the intrinsic change in pulsation frequency, thus providing a cautionary tale. Our analysis shows the potential of the FM technique using {\it Kepler} data, and we discuss the prospects to detect planets and brown dwarfs in Kepler data for A and F stars even in the absence of transits and with no spectroscopic radial velocity curves. This opens the possibility of finding planets orbiting hotter stars that cannot be found by traditional techniques.