OGLE-2019-BLG-1180Lb: Discovery of a Wide-orbit Jupiter-mass Planet around a Late-type Star

We report on the discovery and analysis of the planetary microlensing event OGLE-2019-BLG-1180 with a planet-to-star mass ratio q similar to 0.003. The event OGLE-2019-BLG-1180 has unambiguous cusp-passing and caustic-crossing anomalies, which were caused by a wide planetary caustic with s similar or equal to 2, where s is the star-planet separation in units of the angular Einstein radius theta E. Thanks to well-covered anomalies by the Korea Micorolensing Telescope Network (KMTNet), we measure both the angular Einstein radius and the microlens parallax in spite of a relatively short event timescale of t E = 28 days. However, because of a weak constraint on the parallax, we conduct a Bayesian analysis to estimate the physical lens parameters. We find that the lens system is a super-Jupiter-mass planet of Mp=1.75-0.51+0.53MJ orbiting a late-type star of Mh=0.55-0.26+0.27M circle dot at a distance DL=6.1-1.3+0.9kpc . The projected star-planet separation is a perpendicular to=5.19-1.23+0.90au , which means that the planet orbits at about four times the snow line of the host star. Considering the relative lens-source proper motion of mu rel = 6 mas yr-1, the lens will be separated from the source by 60 mas in 2029. At that time one can measure the lens flux from adaptive optics imaging of Keck or a next-generation 30 m class telescope. OGLE-2019-BLG-1180Lb represents a growing population of wide-orbit planets detected by KMTNet, so we also present a general investigation into prospects for further expanding the sample of such planets.