How eclipse time variations, eclipse duration variations and radial velocities can reveal S-type planets in close eclipsing binaries
How eclipse time variations, eclipse duration variations and radial velocities can reveal S-type planets in close eclipsing binaries
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DOI：
10.1093/mnras/stw3313
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发表时间：
2016-10
影响因子：
4.8
通讯作者：
M. Oshagh;R. Heller;S. Dreizler
中科院分区：
文献类型：
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作者：
M. Oshagh;R. Heller;S. Dreizler
虽然在围绕内部、近距离双星（所谓的“P型行星”）的宽轨道上发现了大约十二颗凌日行星，但尚未发现在食双星中仅围绕一颗恒星（所谓的“S型行星”）运行的行星。尽管开普勒望远镜发现了大量食双星系统，但情况仍然如此。在这里，我们提出了一种针对这些 S 型行星的新检测方法，该方法利用恒星径向速度 (RV)、日食时间变化 (ETV) 和日食持续时间变化 (EDV) 之间的相关性。我们通过模拟真实的基准系统来测试该技术的能力，并通过现有的高精度 RV 和光度测量仪器证明其可检测性。我们说明，通过少量的 RV 观测，RV-ETV 图使我们能够区分顺行和逆行行星轨道，如果可以解开恒星互相关函数，还可以估计行星质量。我们还发现了 S 型行星对食恒星双星中的罗西特-麦克劳林效应的新贡献（尽管很小）。我们最终探索了凌日发光巨行星周围外卫星的可能检测，并发现在其主行星的 RV 曲线中检测卫星所需的精度为 ${\rm cm\,s}^{-1}$ 量级，因此当前的仪器无法达到。
While about a dozen transiting planets have been found in wide orbits around an inner, close stellar binary (so-called "P-type planets"), no planet has yet been detected orbiting only one star (a so-called "S-type planet") in an eclipsing binary. This is despite a large number of eclipsing binary systems discovered with the Kepler telescope. Here we propose a new detection method for these S-type planets, which uses a correlation between the stellar radial velocities (RVs), eclipse timing variations (ETVs), and eclipse duration variations (EDVs). We test the capability of this technique by simulating a realistic benchmark system and demonstrate its detectability with existing high-accuracy RV and photometry instruments. We illustrate that, with a small number of RV observations, the RV-ETV diagrams allows us to distinguish between prograde and retrograde planetary orbits and also the planetary mass can be estimated if the stellar cross-correlation functions can be disentangled. We also identify a new (though minimal) contribution of S-type planets to the Rossiter-McLaughlin effect in eclipsing stellar binaries. We finally explore possible detection of exomoons around transiting luminous giant planets and find that the precision required to detect moons in the RV curves of their host planets is of the order of ${\rm cm\,s}^{-1}$ and therefore not accessible with current instruments.