OGLE-2018-BLG-1700L: Microlensing Planet in Binary Stellar System
Abstract
We report a planet in a binary that was discovered from the analysis of the microlensing event OGLE-2018-BLG-1700. We identify the triple nature of the lens from the fact that the anomaly pattern can be decomposed into two parts produced by two binary-lens events, in which one binary pair has a mass ratio of ∼0.01 between the lens components and the other pair has a mass ratio of ∼0.3. We find two sets of degenerate solutions, in which one solution has a projected separation between the primary and its stellar companion less than the angular Einstein radius {θ }{{E}} (close solution), while the other solution has a separation greater than {θ }{{E}} (wide solution). From the Bayesian analysis with the constraints of the event timescale and angular Einstein radius, we find that the planet has a mass of {4.4}-2.0+3.0 {M}{{J}} and the stellar binary components have masses of {0.42}-0.19+0.29 {M}⊙ and {0.12}-0.05+0.08 {M}⊙ , respectively, and the distance to the lens is {D}{{L}}={7.6}-0.9+1.2 {kpc}. The planet is a circumstellar planet according to the wide solution, while it is a circumbinary planet according to the close solution.
- Publication:
-
The Astronomical Journal
- Pub Date:
- February 2020
- DOI:
- 10.3847/1538-3881/ab5db9
- arXiv:
- arXiv:1909.04854
- Bibcode:
- 2020AJ....159...48H
- Keywords:
-
- Exoplanet systems;
- Binary stars;
- 484;
- 154;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 10 pages, 8 figures