OGLE-2014-BLG-0289

[BjarneModerator Super Nova]

OGLE-2014-BLG-0289: Precise Characterization of a Quintuple-Peak Gravitational Microlensing Event

We present the analysis of the binary-microlensing event OGLE-2014-BLG-0289. The event light curve exhibits very unusual five peaks where four peaks were produced by caustic crossings and the other peak was produced by a cusp approach. It is found that the quintuple-peak features of the light curve provide tight constraints on the source trajectory, enabling us to precisely and accurately measure the microlensing parallax π_E. Furthermore, the three resolved caustics allow us to measure the angular Einstein radius θ_E. From the combination of π_E and θ_E, the physical lens parameters are uniquely determined. It is found that the lens is a binary composed of two M dwarfs with masses M₁ = 0.52±0.04 M_⊙ and M₂=0.42±0.03 M_⊙ separated in projection by a_⊥ = 6.4±0.5 au. The lens is located in the disk with a distance of D_L = 3.3±0.3 kpc. It turns out that the reason for the absence of a lensing signal in the Spitzer data is that the time of observation corresponds to the flat region of the light curve.

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