摘要：We report the discovery and the analysis of the short (${t}_{{\rm{E}}}\lt 5$ days) planetary microlensing event, OGLE-2015-BLG-1771.The event was discovered by the Optical Gravitational Lensing Experiment, and the planetary anomaly (at I ~ 19) was captured by The Korea Microlensing Telescope Network.The event has three surviving planetary models that explain the observed light curves, with planet-host mass ratio q ~ 5.4 × 10−3, 4.5 × 10−3 and 4.5 × 10−2, respectively.The first model is the best-fit model, while the second model is disfavored by Δχ2 ~ 3.The last model is strongly disfavored by Δχ2 ~ 15 but not ruled out.A Bayesian analysis using a Galactic model indicates that the first two models are probably composed of a Saturn-mass planet orbiting a late M dwarf, while the third one could consist of a super-Jovian planet and a mid-mass brown dwarf.The source-lens relative proper motion is μrel ~ 9 mas yr−1, so the source and lens could be resolved by current adaptive-optics instruments in 2020 if the lens is luminous.
