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

August 2020 • 2020AJ....160...74H

Authors • 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 • Li, Man Cheung Alex • 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 • Albrow, Michael D. • 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 • Street, Rachel A. • 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. • von Essen, C. • Fujii, Y. I. • Campbell-White, J. • Lowry, S. • Helling, C. • Mancini, L. • Haikala, L. • MindSTEp Collaboration • Kandori, Ryo • IRSF Team

Abstract • 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 M_planet = 0.41 ± 0.05 M_Jup. The system lies at a distance D_L = 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.

Links

• PREPRINT http://arxiv.org/abs/2004.09067
• ELECTR https://doi.org/10.3847%2F1538-3881%2Fab9ac3
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2020AJ....160...74H
• PDF https://iopscience.iop.org/article/10.3847/1538-3881/ab9ac3/pdf
• PDF https://stacks.iop.org/1538-3881/160/74/pdf
• DATA http://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/160/74
• DATA https://irsa.ipac.caltech.edu/bibdata/2020/H/2020AJ....160...74H.html
• DATA http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?type=REFERENCE&bibcode=2020arXiv200409067H