MOA-2020-BLG-208Lb: Cool Sub-Saturn-mass Planet within Predicted Desert

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American Astronomical Society
(c) 2023 The Author/s
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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=3.17-0.26+0.28×10-4, the planet lies near the peak of the mass-ratio function derived by the MOA collaboration and 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 mplanet=46-24+42M⊕ and a host star of mass Mhost=0.43-0.23+0.39M⊙, located at a distance DL=7.49-1.13+0.99kpc . For the second scenario, we estimate mplanet=69-34+37M⊕, Mhost=0.66-0.32+0.35M⊙, and DL=7.81-0.93+0.93kpc . The planet has a projected separation as a fraction of the Einstein ring radius s=1.3807-0.0018+0.0018 . As a cool sub-Saturn-mass planet, this planet adds to a growing collection of evidence for revised planetary formation models
Binary Lens microlensing, Gravitational Microlensing, Gravitational Microlensing exoplanet detection
Olmschenk G, Bennett DP, Bond IA, Zang W, Jung YK, Yee JC, Bachelet E, Abe F, Barry RK, Bhattacharya A, Fujii H, Fukui A, Hirao Y, Silva SI, Itow Y, Kirikawa R, Kondo I, Koshimoto N, Matsubara Y, Matsumoto S, Miyazaki S, Munford B, Muraki Y, Okamura A, Ranc C, Rattenbury NJ, Satoh Y, Sumi T, Suzuki D, Toda T, Tristram PJ, Vandorou A, Yama H, Albrow MD, Cha SM, Chung SJ, Gould A, Han C, Hwang KH, Kim DJ, Kim HW, Kim SL, Lee CU, Lee DJ, Lee Y, Park BG, Pogge RW, Ryu YH, Shin IG, Shvartzvald Y, Christie G, Cooper T, Drummond J, Green J, Hennerley S, McCormick J, Monard LAG, Natusch T, Porritt I, Tan TG, Mao S, Maoz D, Penny MT, Zhu W, Bozza V, Cassan A, Dominik M, Hundertmark M, Jaimes RF, Kruszyńska K, Rybicki KA, Street RA, Tsapras Y, Wambsganss J, Wyrzykowski , Zieliński P, Rau G. (2023). MOA-2020-BLG-208Lb: Cool Sub-Saturn-mass Planet within Predicted Desert. Astronomical Journal. 165. 4.