OGLE-2016-BLG-1469L: Microlensing Binary Composed of Brown Dwarfs

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 the detection of both finite-source and microlens-parallax effects, we are able to measure both the masses {M}₁˜ 0.05 {M}_⊙ and {M}₂˜ 0.01 {M}_⊙ , and the distance {D}_{{L}}˜ 4.5 {kpc}, as well as the projected separation {a}_\perp ˜ 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 of less than 1 au.