MOA-2020-BLG-208Lb: Cool Sub-Saturn Planet Within Predicted Desert
Creators: name: Olmschenk, Greg
name: Bennett, David P.
name: Bond, Ian A.
name: Zang, Weicheng
name: Jung, Youn Kil
name: Yee, Jennifer C.
name: Bachelet, Etienne
name: Abe, Fumio
name: Barry, Richard K.
name: Bhattacharya, Aparna
name: Fujii, Hirosane
name: Fukui, Akihiko
name: Hirao, Yuki
name: Silva, Stela Ishitani
name: Itow, Yoshitaka
name: Kirikawa, Rintaro
name: Kondo, Iona
name: Koshimoto, Naoki
name: Matsubara, Yutaka
name: Matsumoto, Sho
name: Miyazaki, Shota
name: Munford, Brandon
name: Muraki, Yasushi
name: Okamura, Arisa
name: Ranc, Clément
name: Rattenbury, Nicholas J.
name: Satoh, Yuki
name: Sumi, Takahiro
name: Suzuki, Daisuke
name: Toda, Taiga
name: Tristram, Paul J.
name: Vandorou, Katie
name: Yama, Hibiki
name: Albrow, Michael D.
name: Cha, Sang-Mok
name: Chung, Sun-Ju
name: Gould, Andrew
name: Han, Cheongho
name: Hwang, Kyu-Ha
name: Kim, Dong-Jin
name: Kim, Hyoun-Woo
name: Kim, Seung-Lee
name: Lee, Chung-Uk
name: Lee, Dong-Joo
name: Lee, Yongseok
name: Park, Byeong-Gon
name: Pogge, Richard W.
name: Ryu, Yoon-Hyun
name: Shin, In-Gu
name: Shvartzvald, Yossi
name: Christie, Grant
name: Cooper, Tony
name: Drummond, John
name: Green, Jonathan
name: Hennerley, Steve
name: McCormick, Jennie
name: Monard, L. A. G.
name: Natusch, Tim
name: Porritt, Ian
name: Tan, Thiam-Guan
name: Mao, Shude
name: Maoz, Dan
name: Penny, Matthew T.
name: Zhu, Wei
name: Bozza, V.
name: Cassan, Arnaud
name: Dominik, Martin
name: Hundertmark, Markus
name: Jaimes, R. Figuera
name: Kruszyńska, K.
name: Rybicki, K. A.
name: Street, R. A.
name: Tsapras, Y.
name: Wambsganss, Joachim
name: Wyrzykowski, Ł.
name: Zieliński, P.
name: Rau, Gioia
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We analyze the MOA-2020-BLG-208 gravitational microlensing event and present the discovery and characterization of a new planet, MOA-2020-BLG-208Lb, with an estimated sub-Saturn mass. With a mass ratio $q = 3.17^{+0.28}_{-0.26} \times 10^{-4}$ and a separation $s = 1.3807^{+0.0018}_{-0.0018}$, the planet lies near the peak of the mass-ratio function derived by the MOA collaboration (Suzuki et al. 2016), near the edge of expected sample sensitivity. For these estimates we provide results using two mass law priors: one assuming that all stars have an equal planet-hosting probability, and the other assuming that planets are more likely to orbit around more massive stars. In the first scenario, we estimate that the lens system is likely to be a planet of mass $m_\mathrm{planet} = 46^{+42}_{-24} \; M_\oplus$ and a host star of mass $M_\mathrm{host} = 0.43^{+0.39}_{-0.23} \; M_\odot$, located at a distance $D_L = 7.49^{+0.99}_{-1.13} \; \mathrm{kpc}$. For the second scenario, we estimate $m_\mathrm{planet} = 69^{+37}_{-34} \; M_\oplus$, $M_\mathrm{host} = 0.66^{+0.35}_{-0.32} \; M_\odot$, and $D_L = 7.81^{+0.93}_{-0.93} \; \mathrm{kpc}$. As a cool sub-Saturn-mass planet, this planet adds to a growing collection of evidence for revised planetary formation models and qualifies for inclusion in the extended MOA-II exoplanet microlensing sample.