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arXiv 1003.0340astro-ph.EPastro-ph.SR
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Applegate效应引起的热中子星轨道周期变化

Orbital period variations of hot-Jupiters caused by the Applegate effect

C. A. Watson, T. R. Marsh

摘要:

一些作者已经表明,精确测量系外行星的过境时间变化可能对其他行星体(如系外卫星)敏感。此外,最接近其主星的系外行星的凌日时间变化可以为潮汐耗散理论提供测试。然而,这些研究没有考虑宿主恒星的影响。有大量的观测证据表明,双星的日食时间可以由于恒星活动驱动的恒星四极矩的变化而发生显着变化。在本文中,我们调查和估计这种变化对系外行星过境时间的可能影响。我们发现,在几种情况下,这种变化应该是可检测的。特别是,WASP-18 b的估计周期变化与潮汐耗散的预期变化具有相同的顺序,即使是相对较低的潮汐耗散参数值。由阿普尔盖特机制引起的渡越时间变化也具有正确的量级,并且发生在时间尺度上,因此它们可能会与由于类似彗星的第二颗行星的存在而引起的光时间旅行效应引起的变化混淆。最后,我们认为,过境系外行星系统可能提供一个干净的路线(相比二进制),以约束类型的发电机运行在主恒星。

英文摘要:

Several authors have shown that precise measurements of transit time variations of exoplanets can be sensitive to other planetary bodies, such as exo-moons. In addition, the transit timing variations of the exoplanets closest to their host stars can provide tests of tidal dissipation theory. These studies, however, have not considered the effect of the host star. There is a large body of observational evidence that eclipse times of binary stars can vary dramatically due to variations in the quadrupole moment of the stars driven by stellar activity. In this paper we investigate and estimate the likely impact such variations have on the transit times of exoplanets. We find in several cases that such variations should be detectable. In particular, the estimated period changes for WASP-18b are of the same order as those expected for tidal dissipation, even for relatively low values of the tidal dissipation parameter. The transit time variations caused by the Applegate mechanism are also of the correct magnitude and occur on timescales such that they may be confused with variations caused by light-time travel effects due to the presence of a Jupiter-like second planet. Finally, we suggest that transiting exoplanet systems may provide a clean route (compared to binaries) to constraining the type of dynamo operating in the host star.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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