MOA-bin-29b: A Microlensing Gas-giant Planet Orbiting a Low-mass Host Star
MOA-bin-29b: A Microlensing Gas-giant Planet Orbiting a Low-mass Host Star
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DOI：
10.3847/1538-3881/ab4e9e
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发表时间：
2019-05
期刊：
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通讯作者：
I. Kondo;T. Sumi;D. Bennett;A. Udalski;I. Bond;N. Rattenbury;V. Bozza;Y. Hirao;D. Suzuki;N. Koshimoto;M. Nagakane;S. Miyazaki;F. Abe;R. Barry;A. Bhattacharya;M. Donachie;A. Fukui;H. Fujii;Y. Itow;Y. Kamei;M. Li;Y. Matsubara;T. Matsuo;Y. Muraki;C. Ranc;H. Shibai;H. Suematsu;D. Sullivan;P. Tristram;T. Yamakawa;A. Yonehara;P. Mróz;M. Szymański;I. Soszyński;K. Ulaczyk
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文献类型：
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作者：
I. Kondo;T. Sumi;D. Bennett;A. Udalski;I. Bond;N. Rattenbury;V. Bozza;Y. Hirao;D. Suzuki;N. Koshimoto;M. Nagakane;S. Miyazaki;F. Abe;R. Barry;A. Bhattacharya;M. Donachie;A. Fukui;H. Fujii;Y. Itow;Y. Kamei;M. Li;Y. Matsubara;T. Matsuo;Y. Muraki;C. Ranc;H. Shibai;H. Suematsu;D. Sullivan;P. Tristram;T. Yamakawa;A. Yonehara;P. Mróz;M. Szymański;I. Soszyński;K. Ulaczyk
我们报告了在2006年发生的微透镜事件MOA-bin-29中发现了一颗围绕低质量主星运行的气态巨行星。我们找到了5个简并解，行星/主星质量比为Q∼10−2。所有模型的爱因斯坦半径穿越时间都比较短(∼4-7天)，这表明主星的质量可能很低。根据模型的不同，所测得的透镜源自行为5-9个−1。由于只检测到有限的源效应，我们进行了贝叶斯分析，以获得透镜物理特性的后验概率分布。因此，我们发现透镜系统很可能是一个围绕着银河系凸起中的棕矮星或非常晚的M矮星运行的气态巨星。在误差范围内，五种简并模型的物理参数的概率分布是一致的。通过组合这些概率分布，我们得出结论，透镜系统是一个气态巨星，其质量绕着一颗质量为At的棕矮星运行，恒星-行星投影间隔为。镜头距离很可能在银河系的凸起范围内。
We report the discovery of a gas-giant planet orbiting a low-mass host star in the microlensing event MOA-bin-29 that occurred in 2006. We find five degenerate solutions with the planet/host-star mass ratio of q ∼ 10−2. The Einstein radius crossing time of all models are relatively short (∼4–7 days), which indicates that the mass of host star is likely low. The measured lens-source proper motion is 5–9 mas yr−1 depending on the models. Since only finite source effects are detected, we conduct a Bayesian analysis in order to obtain the posterior probability distribution of the lens physical properties. As a result, we find the lens system is likely to be a gas-giant orbiting a brown dwarf or a very late M-dwarf in the Galactic bulge. The probability distributions of the physical parameters for the five degenerate models are consistent within the range of error. By combining these probability distributions, we conclude that the lens system is a gas giant with a mass of orbiting a brown dwarf with a mass of at a projected star–planet separation of . The lens distance is , i.e., likely within the Galactic bulge.