FM stars: A Fourier view of pulsating binary stars, a new technique for measuring radial velocities photometrically
FM stars: A Fourier view of pulsating binary stars, a new technique for measuring radial velocities photometrically
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DOI：
10.1111/j.1365-2966.2012.20654.x
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发表时间：
2012-02
期刊：
影响因子：
--
通讯作者：
H. Shibahashi;D. Kurtz
中科院分区：
文献类型：
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作者：
H. Shibahashi;D. Kurtz
一些脉动的恒星是很好的时钟。当在双星中发现它们时，它们的光度变化频率受到轨道运动引起的多普勒效应的调制。对于每个脉动频率，在恒星光曲线的傅里叶变换中，这表现为一个被轨道频率隔开的多重态。我们推导了利用傅里叶变换的数据来推导传统上从光谱径向速度提取的二进制系统的所有参数的理论关系，包括质量函数，该函数很容易从每个脉动频率的第一轨道旁瓣与中心频率的幅度比中得到。这是一种从脉动频率的多普勒频移中产生径向速度的新技术，因此不需要获得频谱。对于具有脉动分量的双星，仅从光曲线就可以得到轨道解。我们给出了一个完整的推导，并用人工数据和一个具有开普勒任务数据的等级食双星的情况进行了演示，KIC 4150611(HD 181469)。我们展示了用我们的技术探测木星质量的行星和其他脉动恒星的可能性。我们还展示了如何区分轨道频率倍增和潜在相似的非径向m模倍增，以及如何区分倾斜脉动倍增。
Some pulsating stars are good clocks. When they are found in binary stars, the frequencies of their luminosity variations are modulated by the Doppler effect caused by orbital motion. For each pulsation frequency this manifests itself as a multiplet separated by the orbital frequency in the Fourier transform of the light curve of the star. We derive the theoretical relations to exploit data from the Fourier transform to derive all the parameters of a binary system traditionally extracted from spectroscopic radial velocities, including the mass function which is easily derived from the amplitude ratio of the first orbital sidelobes to the central frequency for each pulsation frequency. This is a new technique that yields radial velocities from the Doppler shift of a pulsation frequency, thus eliminates the need to obtain spectra. For binary stars with pulsating components, an orbital solution can be obtained from the light curve alone. We give a complete derivation of this and demonstrate it both with artificial data, and with a case of a hierarchical eclipsing binary with {\it Kepler} mission data, KIC 4150611 (HD 181469). We show that it is possible to detect Jupiter-mass planets orbiting $\delta$ Sct and other pulsating stars with our technique. We also show how to distinguish orbital frequency multiplets from potentially similar nonradial $m$-mode multiplets and from oblique pulsation multiplets.