Brown Dwarf OGLE-2015-BLG-1268 Discovered via Microlensing

Mass Measurements of Isolated Objects from Space-based Microlensing

Authors:

Zhu et al

Abstract:

We report on the mass and distance measurements of two single-lens events from the 2015 Spitzer microlensing campaign. With both finite-source effect and microlens parallax measurements, we find that the lens of OGLE-2015-BLG-1268 is a 47±7 MJ brown dwarf at 5.4±1.0 kpc, and that the lens of OGLE-2015-BLG-0763 is a 0.50±0.04 M⊙ star at 6.9±1.0 kpc. We show that the probability to definitively measure the mass of isolated microlenses, including isolated stellar mass black holes and free floating planets, is dramatically increased once simultaneous ground- and space-based observations are conducted.