OGLE-2018-BLG-1700L: Microlensing Planet in Binary Stellar System

Han, Cheongho; Lee, Chung-Uk; Udalski, Andrzej; Gould, Andrew; Bond, Ian A.; AUTHORS, LEADING; Albrow, Michael D.; Chung, Sun-Ju; Hwang, Kyu-Ha; Jung, Youn Kil et al.
Referencia bibliográfica

The Astronomical Journal

Fecha de publicación:
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}ȯ and {0.12}-0.05+0.08 {M}ȯ , 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.