OGLE-2017-BLG-1049: Another microlensing event with a giant planet

We report a giant exoplanet discovery in the microlensing event OGLE-2017-BLG1049, which is a planet-host star mass ratio of q = 9.53± 0.39× 10−3 and has a caustic crossing feature in the Korea Microlensing Telescope Network (KMTNet) observations. The caustic crossing feature yields an angular Einstein radius of θE = 0.52± 0.11 mas. However, the microlens parallax is not measured because of the time scale of the event tE ' 29 days, which is not long enough in this case to determine the microlens parallax. Thus, we perform a Bayesian analysis to estimate physical quantities of the lens system. From this, we find that the lens system has a star with mass Mh = 0.55 +0.36 −0.29 M hosting a giant planet with Mp = 5.53 +3.62 −2.87 MJup, at a distance of DL = 5.67 +1.11 −1.52 kpc. The projected star-planet separation in units of the Einstein radius (θE) corresponding to the total mass of the lens system is a⊥ = 3.92 +1.10 −1.32 au. This means that the planet is located beyond the snow line of the host. The relative lens-source proper motion is μrel ∼ 7 mas yr−1, thus the lens and source will be separated from each other within 10 years. Then the flux of the host star can be measured by a 30m class telescope with high-resolution imaging in the future, and thus its mass can be determined.