Year: 2019
Type: article
Abstract: 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.
Source: The Astronomical Journal
Authors: Iona Kondo, Takahiro Sumi, David P. Bennett, Andrzej Udalski, Ian A. Bond, Nicholas J. Rattenbury, Valerio Bozza, Yuki Hirao, Daisuke Suzuki, Naoki Koshimoto, Masayuki Nagakane, Shota Miyazaki, F. Abe, R. Barry, A. Bhattacharya, M. Donachie, A. Fukui, H. Fujii, Y. Itow, Y. Kamei, M. C. A. Li, Y. Matsubara, T. Matsuo, Y. Muraki, C. Ranc, H. Shibai, H. Suematsu, D. J. Sullivan, P. J. Tristram, T. Yamakawa, A. Yonehara, P. Mróz, M. K. Szymański, I. Soszyński, K. Ulaczyk
Institutions: The University of Osaka, Goddard Space Flight Center, University of Maryland, College Park, University of Warsaw, Massey University, University of Auckland, University of Salerno, Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, National Astronomical Observatory of Japan, The University of Tokyo, Institute for Space-Earth Environmental Research, Nagoya University, Nagoya University, Instituto de Astrofísica de Canarias, Victoria University of Wellington, University of Canterbury, Kyoto Sangyo University, University of Warwick
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: 重力マイクロレンズ法による惑星存在率の銀河系内分布及び主星質量依存性の推定, THE PI PROPOSES TO CONTINUE HIS WORK WITH THE MOA COLLABORATION TO SEARCH FOR COLD, LOW-MASS PLANETS THAT ORBIT BEYOND THE SNOW LINE OR ARE NOT BOUND, G2231741338, Microlensing Survey for Exoplanets beyond the Snow Line, 重力マイクロレンズ法によるＭ型星周りの地球質量～恒星質量までの伴星の存在量の制限, G4831422839, Search for extrasolar planets with microlensing, G5619241798, Search for extrasolar planets with microlensing follow-up observations, G6996030003, 世界初の近赤外線による重力マイクロレンズ法を用いた系外惑星探査, Search for cold exoplanets and free-floating planets by near infrared gravitational microlensing observation, G7558095811, G8102657827
OpenAlex ID: W2943257203