Exoplanets & Exomoons

An Earth-mass Planet in a 1-AU Orbit Around a Brown Dwarf

By Keith Cowing
Press Release
March 27, 2017
Filed under
An Earth-mass Planet in a 1-AU Orbit Around a Brown Dwarf

We combine Spitzer and ground-based KMTNet microlensing observations to identify and precisely measure an Earth-mass (1.32+0.41−0.28M⊕) planet OGLE-2016-BLG-1195Lb at 1.11+0.13−0.10 AU orbiting a 0.072+0.014−0.010M⊙ ultracool dwarf, likely a brown dwarf.

This is the lowest-mass microlensing planet to date. At 4.20+0.29−0.34 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 brown dwarfs and planetary systems at the limit of low-mass protoplanetary disks.

Y. Shvartzvald, J. C. Yee, S. Calchi Novati, A. Gould, C.-U. Lee, C. Beichman, G. Bryden, S. Carey, B. S. Gaudi, C. B. Henderson, W. Zhu, M. D. Albrow, S.-M. Cha, S.-J. Chung, C. Han, K.-H. Hwang, Y. K. Jung, D.-J. Kim, H.-W. Kim, S.-L. Kim, Y. Lee, B.-G. Park, R. W. Pogge, Y.-H. Ryu, I.-G. Shin
(Submitted on 24 Mar 2017)

Comments: 17 pages, 3 figures, 2 tables. Submitted to ApJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1703.08548 [astro-ph.EP] (or arXiv:1703.08548v1 [astro-ph.EP] for this version)
Submission history
From: Yossi Shvartzvald
[v1] Fri, 24 Mar 2017 18:00:01 GMT (539kb,D)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻