OGLE-2016-BLG-1469L: Microlensing Binary Composed of Brown Dwarfs
astro-ph.SR
/ Authors
C. Han, A. Udalski, T. Sumi, A. Gould, M. D. Albrow, S. -J. Chung, Y. K. Jung, Y. -H. Ryu, I. -G. Shin, J. C. Yee
and 44 more authors
W. Zhu, S. -M. Cha, S. -L. Kim, D. -J. Kim, C. -U. Lee, Y. Lee, B. -G. Park, I. Soszyński, P. Mróz, P. Pietrukowicz, M. K. Szymański, J. Skowron R. Poleski, S. Kozłowski, K. Ulaczyk, M. Pawlak, F. Abe, Y. Asakura, D. P. Bennett, I. A. Bond, A. Bhattacharya, M. Donachie, M. Freeman, A. Fukui, Y. Hirao
/ Abstract
We report the discovery of a binary composed of two brown dwarfs, based on the analysis of the microlensing event OGLE-2016-BLG-1469. Thanks to detection of both finite-source and microlens-parallax effects, we are able to measure both the masses $M_1\sim 0.05\ M_\odot$, $M_2\sim 0.01\ M_\odot$, and distance $D_{\rm L} \sim 4.5$ kpc, as well as the projected separation $a_\perp \sim 0.33$ au. This is the third brown-dwarf binary detected using the microlensing method, demonstrating the usefulness of microlensing in detecting field brown-dwarf binaries with separations less than 1 au.