Ogle-2012-blg-0724lb: A Saturn Mass Planet Around an M-dwarf

We report the discovery of a planet by the microlensing method, OGLE2012-BLG-0724Lb. Although the duration of the planetary signal for this event was one of the shortest seen for a planetary event, the anomaly was well covered thanks to high cadence observations taken by the survey groups OGLE and MOA. By analyzing the light curve, this planetary system is found to have a mass ratio q = (1.58 ± 0.15) × 10−3. By conducting a Bayesian analysis, we estimate that the host star is an M-dwarf star with a mass of ML = 0.29 +0.33 −0.16 M located at DL = 6.7 +1.1 −1.2 kpc away from the Earth and the companion’s mass is mP = 0.47 +0.54 −0.26 MJup. The projected planet-host separation is a⊥ = 1.6 +0.4 −0.3 AU. Depertment of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan Microlensing Observations in Astrophysics (MOA) Warsaw University Observatory, A1. Ujazdowski 4, 00-478 Warszawa, Poland Optical Gravitational Lens Experiment (OGLE) Department of Physics, University of Notre Dame, Norte Dame, IN 46556, USA Laboratory for Exoplanets and Stellar Astrophysics, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA Department of Physics, University of Auckland, Private Bag 92019, Auckland, New Zealand Institute for Space-Earth Environmental Research, Nagoya University, Nagoya 464-8601, Japan Department of Physics, University of Auckland, Private Bag 92019, Auckland, New Zealand Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, 3037-5 Honjo, Kamogata, Asakuchi, Okayama 719-0232, Japan Institute of Information and Mathematical Sciences, Massey University, Private Bag 102-904, North Shore Mail Centre, Auckland, New Zealand Nagano National College of Technology, Nagano 381-8550, Japan Tokyo Metropolitan College of Aeronautics, Tokyo 116-8523, Japan School of Chemical and Physical Sciences, Victoria University, Wellington, New Zealand Mt. John University Observatory, P.O. Box 56, Lake Tekapo 8770, New Zealand Department of Physics, Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555, Japan Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210, USA Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK