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}<SUB>1</SUB>˜ 0.05 {M}<SUB>⊙ </SUB> and {M}<SUB>2</SUB>˜ 0.01 {M}<SUB>⊙ </SUB>, and the distance {D}<SUB>{{L</SUB>}}˜ 4.5 {kpc}, as well as the projected separation {a}<SUB>\perp </SUB>˜ 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.