文章基本信息

标题：OGLE-2018-BLG-1011Lb,c: Microlensing Planetary System with Two Giant Planets Orbiting a Low-mass Star
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作者：Cheongho Han ; David P. Bennett ; Andrzej Udalski 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2019
卷号：158
期号：3
页码：1-15
DOI：10.3847/1538-3881/ab2f74
语种：English
出版社：American Institute of Physics
摘要：We report a multiplanetary system found from the analysis of microlensing event OGLE-2018-BLG-1011, for which the light curve exhibits a double-bump anomaly around the peak. We find that the anomaly cannot be fully explained by the binary-lens or binary-source interpretations and its description requires the introduction of an additional lens component. The 3L1S (three lens components and a single source) modeling yields three sets of solutions, in which one set of solutions indicates that the lens is a planetary system in a binary, while the other two sets imply that the lens is a multiplanetary system. By investigating the fits of the individual models to the detailed light curve structure, we find that the multiple-planet solution with planet-to-host mass ratios ∼9.5×10 −3 and ∼15×10 −3 are favored over the other solutions. From the Bayesian analysis, we find that the lens is composed of two planets with masses - + M 1.8 1.1 3..4 J and - + M 2.8 1.7 5.1 J around a host with a mass - + M 0.18 0.10 0.33 and located at a distance - + 7.1 kpc 1.5 1.1 . The estimated distance indicates that the lens is the farthest system among the known multiplanetary systems. The projected planet–host separations are = ^ -+ a 1.8 au ,2 1.5 2.1 ( - + 0.8 au 0.6 0.9 ) and = ^ - + a 0.8 au ,3 0.6 0.9 , where the values of a ⊥,2 inside and outside the parenthesis are the separations corresponding to the two degenerate solutions, indicating that both planets are located beyond the snow line of the host, as with the other four multiplanetary systems previously found by microlensing.
关键词：gravitational lensing: micro;planetary systems