文章基本信息

标题：A companion on the planet/brown dwarf mass boundary on a wide orbit discovered by gravitational microlensing
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作者：R. Poleski ; R. Poleski ; A. Udalski 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2017
卷号：604
页码：1-8
DOI：10.1051/0004-6361/201730928
语种：English
出版社：EDP Sciences
摘要：We present the discovery of a substellar companion to the primary host lens in the microlensing event MOA-2012-BLG-006. The companion-to-host mass ratio is 0.016, corresponding to a companion mass of ≈8 MJup(M∗/ 0.5 M⊙). Thus, the companion is either a high-mass giant planet or a low-mass brown dwarf, depending on the mass of the primary M∗. The companion signal was separated from the peak of the primary event by a time that was as much as four times longer than the event timescale. We therefore infer a relatively large projected separation of the companion from its host of ≈10 au(M∗/ 0.5 M⊙)1 / 2 for a wide range (3–7 kpc) of host star distances from the Earth. We also challenge a previous claim of a planetary companion to the lens star in microlensing event OGLE-2002-BLG-045.
关键词：engravitational lensing: microinstrumentation: high angular resolutionplanetary systemsbrown dwarfs