OGLE-2018-BLG-1011Lb,c: Microlensing Planetary System with Two Giant Planets Orbiting a Low-mass Star

Cheongho Han , David P. Bennett , Andrzej Udalski , Andrew Gould , Ian A. Bond , Yossi Shvartzvald , Kay-Sebastian Nikolaus , Markus Hundertmark , Valerio Bozza , Arnaud Cassan (1) , Yuki Hirao , Etienne Bachelet , Pascal Fouqué (2) , Michael D. Albrow , Sun-Ju Chung , Kyeongsoo Hong , Kyu-Ha Hwang , Chung-Uk Lee , Yoon-Hyun Ryu , In-Gu Shin , Jennifer C. Yee , Youn Kil Jung , Sang-Mok Cha , Doeon Kim , Dong-Jin Kim , Hyoun-Woo Kim , Seung-Lee Kim , Dong-Joo Lee , Yongseok Lee , Byeong-Gon Park , Richard W. Pogge , Przemek Mróz , Michał K. Szymański , Jan Skowron , Radek Poleski , Igor Soszyński , Paweł Pietrukowicz , Szymon Kozłowski , Krzysztof Ulaczyk , Krzysztof A. Rybicki , Patryk Iwanek , Marcin Wrona , Fumio Abe , Richard Barry , Aparna Bhattacharya , Martin Donachie , Akihiko Fukui , Yoshitaka Itow , Kohei Kawasaki , Iona Kondo , Naoki Koshimoto , Man Cheung Alex Li , Yutaka Matsubara , Yasushi Muraki , Shota Miyazaki , Masayuki Nagakane , Clément Ranc , Nicholas J. Rattenbury , Haruno Suematsu , Denis J. Sullivan , Takahiro Sumi , Daisuke Suzuki , Paul J. Tristram , Atsunori Yonehara , Shude Mao , Tianshu Wang , Weicheng Zang , Wei Zhu , Matthew T. Penny , Charles A. Beichman , Geoffery Bryden , Sebastiano Calchi Novati , B. Scott Gaudi , Calen B. Henderson , Savannah Jacklin , Keivan G. Stassun

1 IAP - Institut d'Astrophysique de Paris
2 CFHT - Canada-France-Hawaii Telescope Corporation

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 {1.8}_-1.1^+3..4 {M}_{{J}} and {2.8}_-1.7^+5.1 {M}_{{J}} around a host with a mass {0.18}_-0.10^+0.33 {M}_⊙ and located at a distance {7.1}_-1.5^+1.1 {kpc}. The estimated distance indicates that the lens is the farthest system among the known multiplanetary systems. The projected planet-host separations are {a}_{\perp ,2}={1.8}_-1.5^+2.1 {au} ({0.8}_-0.6^+0.9 {au}) and {a}_{\perp ,3}={0.8}_-0.6^+0.9 {au}, 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.

Mots clés: gravitational lensing: micro; planetary systems; Astrophysics - Earth and Planetary Astrophysics

Domaines: Planète et Univers [physics]

Cheongho Han, David P. Bennett, Andrzej Udalski, Andrew Gould, Ian A. Bond, et al.. OGLE-2018-BLG-1011Lb,c: Microlensing Planetary System with Two Giant Planets Orbiting a Low-mass Star. The Astronomical Journal, 2019, 158, ⟨10.3847/1538-3881/ab2f74⟩. ⟨insu-03674410⟩