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arXiv 1509.01136astro-ph.EPastro-ph.SR
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从木星的卫星上看地球凌日:探测到由冰冷的木卫二的反对派涌动产生的逆Rossiter-McLaughlin效应

The Earth transiting the Sun as seen from Jupiter's moons: detection of an inverse Rossiter-McLaughlin effect produced by the Opposition Surge of the icy Europa

Paolo Molaro, Mauro Barbieri, Lorenzo Monaco, Simone Zaggia, Christophe Lovis

摘要:

我们报告了2014年1月5日从木星上看到的地球在太阳上的过境之后的多波长观测活动。同时观测木星的卫星木卫二和木卫三,使用来自智利拉西拉的HARPS和来自加那利群岛拉帕尔马的HARPS-N,使用与2012年金星凌日成功采用的相同技术(Molaro等人,2013年)测量由于地球通过而引起的Rossiter-McLaughlin效应。径向速度的预期调制约为20 cm/s,但检测到高达38 m/s的异常漂移,即高出两个数量级以上且符号相反。两个光谱仪的一致行为排除了径向速度漂移的仪器来源,BiSON观测排除了对太阳磁活动的可能依赖。我们认为,这种异常是由木卫二的冰面上的反对派浪涌,它放大了太阳辐射的强度,从太阳表面的一部分,围绕交叉地球,然后可以观察到一种逆罗斯特-麦克劳克林效应。事实上,这种效应的简化模型可以详细解释观测到的径向速度异常的大部分特征,即凌日前后的延伸、两个观测站之间的微小差异以及更靠近地球通道的次峰的存在。这种现象是第一次在这里观察到的,每次类似的地球对齐发生在没有大气层的岩石体上时都应该观察到。我们预测它应该在2026年地球和木星的下一次结合中再次被观察到。

英文摘要:

We report on a multi-wavelength observational campaign which followed the Earth's transit on the Sun as seen from Jupiter on 5 Jan the 2014. Simultaneous observations of Jupiter's moons Europa and Ganymede obtained with HARPS from La Silla, Chile, and HARPS-N from La Palma, Canary Islands, were performed to measure the Rossiter-McLaughlin effect due to the Earth's passage using the same technique successfully adopted for the 2012 Venus Transit (Molaro et al 2013). The expected modulation in radial velocities was of about 20 cm/s but an anomalous drift as large as 38 m/s, i.e. more than two orders of magnitude higher and opposite in sign, was detected instead. The consistent behaviour of the two spectrographs rules out instrumental origin of the radial velocity drift and BiSON observations rule out the possible dependence on the Sun's magnetic activity. We suggest that this anomaly is produced by the Opposition Surge on Europa's icy surface, which amplifies the intensity of the solar radiation from a portion of the solar surface centered around the crossing Earth which can then be observed as a a sort of inverse Rossiter-McLaughling effect. in fact, a simplified model of this effect can explain in detail most features of the observed radial velocity anomalies, namely the extensions before and after the transit, the small differences between the two observatories and the presence of a secondary peak closer to Earth passage. This phenomenon, observed here for the first time, should be observed every time similar Earth alignments occur with rocky bodies without atmospheres. We predict it should be observed again during the next conjunction of Earth and Jupiter in 2026.

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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