OGLE-2016-BLG-0156: Microlensing Event with Pronounced Microlens-parallax Effects Yielding a Precise Lens Mass Measurement
Abstract
We analyze the gravitational binary-lensing event OGLE-2016-BLG-0156, for which the lensing light curve displays pronounced deviations induced by microlens-parallax effects. The light curve exhibits three distinctive widely separated peaks and we find that the multiple-peak feature provides a very tight constraint on the microlens-parallax effect, enabling us to precisely measure the microlens parallax {π }{{E}}. All the peaks are densely and continuously covered from high-cadence survey observations using globally located telescopes and the analysis of the peaks leads to the precise measurement of the angular Einstein radius {θ }{{E}}. From the combination of the measured {π }{{E}} and {θ }{{E}}, we determine the physical parameters of the lens. It is found that the lens is a binary composed of two M dwarfs with masses M 1 = 0.18 ± 0.01 M ⊙ and M 2 = 0.16 ± 0.01 M ⊙ located at a distance {D}{{L}}=1.35+/- 0.09 {kpc}. According to the estimated lens mass and distance, the flux from the lens comprises an important fraction, ∼25%, of the blended flux. The bright nature of the lens combined with the high relative lens-source motion, μ = 6.94 ± 0.50 mas yr-1, suggests that the lens can be directly observed from future high-resolution follow-up observations.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2019
- DOI:
- 10.3847/1538-4357/ab001f
- arXiv:
- arXiv:1901.06457
- Bibcode:
- 2019ApJ...872..175J
- Keywords:
-
- binaries: general;
- gravitational lensing: micro;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 9 pages, 9 figures