Bibcode
Jung, Youn Kil; Gould, Andrew; Udalski, Andrzej; Sumi, Takahiro; Yee, Jennifer C.; Shvartzvald, Yossi; Zang, Weicheng; and; Han, Cheongho; Albrow, Michael D.; Chung, Sun-Ju; Hwang, Kyu-Ha; Ryu, Yoon-Hyun; Shin, In-Gu; Zhu, Wei; Cha, Sang-Mok; Kim, Dong-Jin; Kim, Hyoun-Woo; Kim, Seung-Lee; Lee, Chung-Uk; Lee, Dong-Joo; Lee, Yongseok; Park, Byeong-Gon; Pogge, Richard W.; (The KMTNet Collaboration; Mróz, Przemek; Szymański, Michał K.; Skowron, Jan; Poleski, Radek; Soszyński, Igor; Pietrukowicz, Paweł; Kozłowski, Szymon; Ulaczyk, Krzystof; Rybicki, Krzysztof A.; Iwanek, Patryk; Wrona, Marcin; (The OGLE Collaboration; Beichman, Charles A.; Bryden, Geoffery; Calchi Novati, Sebastiano; Carey, Sean; Gaudi, B. Scott; Henderson, Calen B.; (The Spitzer Team; Abe, Fumio; Barry, Richard; Bennett, David P.; Bond, Ian A.; Bhattacharya, Aparna; Donachie, Martin; Fukui, Akihiko; Hirao, Yuki; Itow, Yoshitaka; Kondo, Iona; Koshimoto, Naoki; Li, Man Cheung Alex; Matsubara, Yutaka; Miyazaki, Shota; Muraki, Yasushi; Nagakane, Masayuki; Ranc, Clément; Rattenbury, Nicholas J.; Suematsu, Haruno; Sullivan, Denis J.; Suzuki, Daisuke; Tristram, Paul J.; Yonehara, Atsunori; (The MOA Collaboration; Jacklin, Savannah; Penny, Matthew T.; Stassun, Keivan G.; (The UKIRT Microlensing Team; Fouqué, Pascal; Mao, Shude; Wang, Tianshu; (The CFHT Microlensing Collaboration
Bibliographical reference
The Astronomical Journal, Volume 158, Issue 1, article id. 28, 13 pp. (2019).
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7
2019
Citations
19
Refereed citations
18
Description
We report the discovery of a Spitzer microlensing planet
OGLE-2018-BLG-0596Lb, with preferred planet-host mass ratio q ∼ 2
× 10‑4. The planetary signal, which is
characterized by a short (∼1 day) “bump” on the rising
side of the lensing light curve, was densely covered by ground-based
surveys. We find that the signal can be explained by a bright source
that fully envelops the planetary caustic, i.e., a
“Hollywood” geometry. Combined with the source proper motion
measured from Gaia, the Spitzer satellite parallax measurement makes it
possible to precisely constrain the lens physical parameters. The
preferred solution, in which the planet perturbs the minor image due to
lensing by the host, yields a Uranus-mass planet with a mass of M
p = 13.9 ± 1.6 M ⊕ orbiting a mid
M-dwarf with a mass of M h = 0.23 ± 0.03 M
⊙. There is also a second possible solution that is
substantially disfavored but cannot be ruled out, for which the planet
perturbs the major image. The latter solution yields M p =
1.2 ± 0.2 M ⊕ and M h = 0.15 ±
0.02 M ⊙. By combining the microlensing and Gaia data
together with a Galactic model, we find in either case that the lens
lies on the near side of the Galactic bulge at a distance D L
∼ 6 ± 1 kpc. Future adaptive optics observations may
decisively resolve the major image/minor image degeneracy.