An Earth-mass Planet in a 1 au Orbit around an Ultracool Dwarf

May 2017 • 2017ApJ...840L...3S

Authors • Shvartzvald, Y. • Yee, J. C. • Calchi Novati, S. • Gould, A. • Lee, C. -U. • Beichman, C. • Bryden, G. • Carey, S. • Gaudi, B. S. • Henderson, C. B. • Zhu, W. • Spitzer Team • Albrow, M. D. • Cha, S. -M. • Chung, S. -J. • Han, C. • Hwang, K. -H. • Jung, Y. K. • Kim, D. -J. • Kim, H. -W. • Kim, S. -L. • Lee, Y. • Park, B. -G. • Pogge, R. W. • Ryu, Y. -H. • Shin, I. -G. • KMTNet Group

Abstract • We combine Spitzer and ground-based Korea Microlensing Telescope Network microlensing observations to identify and precisely measure an Earth-mass ({1.43}_-0.32^+0.45{M}_\oplus ) planet OGLE-2016-BLG-1195Lb at {1.16}_-0.13^+0.16 {au} orbiting a {0.078}_-0.012^+0.016{M}_⊙ ultracool dwarf. This is the lowest-mass microlensing planet to date. At {3.91}_-0.46^+0.42 kpc, it is the third consecutive case among the Spitzer “Galactic distribution” planets toward the Galactic bulge that lies in the Galactic disk as opposed to the bulge itself, hinting at a skewed distribution of planets. Together with previous microlensing discoveries, the seven Earth-size planets orbiting the ultracool dwarf TRAPPIST-1, and the detection of disks around young brown dwarfs, OGLE-2016-BLG-1195Lb suggests that such planets might be common around ultracool dwarfs. It therefore sheds light on the formation of both ultracool dwarfs and planetary systems at the limit of low-mass protoplanetary disks.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2017ApJ...840L...3S
• PDF https://iopscience.iop.org/article/10.3847/2041-8213/aa6d09/pdf
• PREPRINT http://arxiv.org/abs/1703.08548
• DATA http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?type=REFERENCE&bibcode=2017ApJ...840L...3S
• DATA https://irsa.ipac.caltech.edu/bibdata/2017/S/2017ApJ...840L...3S.html
• ELECTR https://iopscience.iop.org/article/10.3847/2041-8213/aa6d09