OGLE-2017-BLG-0406: Spitzer Microlens Parallax Reveals Saturn-mass Planet Orbiting M-dwarf Host in the Inner Galactic Disk

Hirao, Yuki; Bennett, David P.; Ryu, Yoon-Hyun; Koshimoto, Naoki; Udalski, Andrzej; Yee, Jennifer C.; Sumi, Takahiro; Bond, Ian A.; Shvartzvald, Yossi; Abe, Fumio; Barry, Richard K.; Bhattacharya, Aparna; Donachie, Martin; Fukui, Akihiko; Itow, Yoshitaka; Kondo, Iona; Alex Li, Man Cheung; Matsubara, Yutaka; Matsuo, Taro; Miyazaki, Shota; Muraki, Yasushi; Nagakane, Masayuki; Ranc, Clément; Rattenbury, Nicholas J.; Suematsu, Haruno; Shibai, Hiroshi; Suzuki, Daisuke; Tristram, Paul J.; Yonehara, Atsunori; MOA Collaboration; Skowron, J.; Poleski, R.; Mróz, P.; Szymański, M. K.; Soszyński, I.; Kozłowski, S.; Pietrukowicz, P.; Ulaczyk, K.; Rybicki, K.; Iwanek, P.; OGLE Collaboration; D. Albrow, Michael; Chung, Sun-Ju; Gould, Andrew; Han, Cheongho; Hwang, Kyu-Ha; Jung, Youn Kil; Shin, In-Gu; Zang, Weicheng; 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.; KMTNet Collaboration; Beichman, Charles A.; Bryden, Geoffery; Novati, Sebastiano Calchi; Carey, Sean; Gaudi, B. Scott; Henderson, Calen B.; Zhu, Wei; Spitzer Team; Bachelet, Etienne; Bolt, Greg; Christie, Grant; Hundertmark, Markus; Natusch, Tim; Maoz, Dan; McCormick, Jennie; A. Street, Rachel; Tan, Thiam-Guan; Tsapras, Yiannis; LCO and μFUN Follow-up Teams; Jørgensen, U. G.; Dominik, M.; Bozza, V.; Skottfelt, J.; Snodgrass, C.; Ciceri, S.; Jaimes, R. Figuera; Evans, D. F.; Peixinho, N.; Hinse, T. C.; Burgdorf, M. J.; Southworth, J.; Rahvar, S.; Sajadian, S.; Rabus, M.; Essen, C. von; Fujii, Y. I.; Campbell-White, J.; Lowry, S.; Helling, C.; Mancini, L.; Haikala, L. et al.
Bibliographical reference

The Astronomical Journal

Advertised on:
8
2020
Number of authors
103
IAC number of authors
1
Citations
19
Refereed citations
17
Description
We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the Spitzer satellite in a solar orbit. At high magnification, the anomaly in the light curve was densely observed by ground-based-survey and follow-up groups, and it was found to be explained by a planetary lens with a planet/host mass ratio of $q=7.0\times {10}^{-4}$?--> <!-- --> from the light-curve modeling. The ground-only and Spitzer-"only" data each provide very strong one-dimensional (1D) constraints on the 2D microlens parallax vector ${{\boldsymbol{\pi }}}_{{\rm{E}}}$?--> <!-- --> . When combined, these yield a precise measurement of ${{\boldsymbol{\pi }}}_{{\rm{E}}}$?--> <!-- --> and of the masses of the host ${M}_{\mathrm{host}}=0.56\pm 0.07\,{M}_{\odot }$?--> <!-- --> and planet Mplanet = 0.41 ± 0.05 MJup. The system lies at a distance DL = 5.2 ± 0.5 kpc from the Sun toward the Galactic bulge, and the host is more likely to be a disk population star according to the kinematics of the lens. The projected separation of the planet from the host is ${a}_{\perp }=3.5\pm 0.3\,\mathrm{au}$?--> <!-- --> (i.e., just over twice the snow line). The Galactic-disk kinematics are established in part from a precise measurement of the source proper motion based on OGLE-IV data. By contrast, the Gaia proper-motion measurement of the source suffers from a catastrophic 10σ error.