OGLE-2018-BLG-0799Lb: a $q \sim 2.7 \times 10^{-3}$ Planet with Spitzer Parallax
Creators: name: Zang, Weicheng
name: Shvartzvald, Yossi
name: Udalski, Andrzej
name: Yee, Jennifer C.
name: Lee, Chung-Uk
name: Sumi, Takahiro
name: Zhang, Xiangyu
name: Yang, Hongjing
name: Mao, Shude
name: Novati, Sebastiano Calchi
name: Gould, Andrew
name: Zhu, Wei
name: Beichman, Charles A.
name: Bryden, Geoffery
name: Carey, Sean
name: Gaudi, B. Scott
name: Henderson, Calen B.
name: Mróz, Przemek
name: Skowron, Jan
name: Poleski, Radoslaw
name: Szymański, Michał K.
name: Soszyński, Igor
name: Pietrukowicz, Paweł
name: Kozłowski, Szymon
name: Ulaczyk, Krzysztof
name: Rybicki, Krzysztof A.
name: Iwanek, Patryk
name: Wrona, Marcin
name: Albrow, Michael D.
name: Chung, Sun-Ju
name: Han, Cheongho
name: Hwang, Kyu-Ha
name: Jung, Youn Kil
name: Ryu, Yoon-Hyun
name: Shin, In-Gu
name: Cha, Sang-Mok
name: Kim, Dong-Jin
name: Kim, Hyoun-Woo
name: Kim, Seung-Lee
name: Lee, Dong-Joo
name: Lee, Yongseok
name: Park, Byeong-Gon
name: Pogge, Richard W.
name: Bond, Ian A.
name: Abe, Fumio
name: Barry, Richard
name: Bennett, David P.
name: Bhattacharya, Aparna
name: Donachie, Martin
name: Fujii, Hirosane
name: Fukui, Akihiko
name: Hirao, Yuki
name: Itow, Yoshitaka
name: Kirikawa, Rintaro
name: Kondo, Iona
name: Koshimoto, Naoki
name: Li, Man Cheung Alex
name: Matsubara, Yutaka
name: Muraki, Yasushi
name: Miyazaki, Shota
name: Ranc, Clément
name: Rattenbury, Nicholas J.
name: Satoh, Yuki
name: Shoji, Hikaru
name: Suzuki, Daisuke
name: Tanaka, Yuzuru
name: Tristram, Paul J.
name: Yamawaki, Tsubasa
name: Yonehara, Atsunori
name: Bachelet, Etienne
name: Hundertmark, Markus P. G.
name: Jaimes, R. Figuera
name: Maoz, Dan
name: Penny, Matthew T.
name: Street, Rachel A.
name: Tsapras, Yiannis
Publisher: name: arXiv
Year: 2020
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 report the discovery and analysis of a planet in the microlensing event OGLE-2018-BLG-0799. The planetary signal was observed by several ground-based telescopes, and the planet-host mass ratio is $q = (2.65 \pm 0.16) \times 10^{-3}$. The ground-based observations yield a constraint on the angular Einstein radius $θ_{\rm E}$, and the microlensing parallax vector $\vecπ_{\rm E}$, is strongly constrained by the Spitzer data. However, the 2019 Spitzer baseline data reveal systematics in the Spitzer photometry, so there is ambiguity in the magnitude of the parallax. In our preferred interpretation, a full Bayesian analysis using a Galactic model indicates that the planetary system is composed of an $M_{\rm planet} = 0.26_{-0.11}^{+0.22}~M_{J}$ planet orbiting an $M_{\rm host} = 0.093_{-0.038}^{+0.082}~M_{\odot}$, at a distance of $D_{\rm L} = 3.71_{-1.70}^{+3.24}$ kpc. An alternate interpretation of the data shifts the localization of the minima along the arc-shaped microlens parallax constraints. This, in turn, yields a more massive host with median mass of $0.13 {M_{\odot}}$ at a distance of 6.3 kpc. This analysis demonstrates the robustness of the osculating circles formalism, but shows that further investigation is needed to assess how systematics affect the specific localization of the microlens parallax vector and, consequently, the inferred physical parameters.
description: Published by MNRAS