extrasolar giant planet around the star OGLE - TR - 113

We report the independent discovery of a new extrasolar transiting planet around OGLE-TR-113, a candidate star from the Optical Gravitational Lensing Experiment. Small radial-velocity variations have been detected based on observations conducted with the MIKE spectrograph on the Magellan I (Baade) telescope at the Las Campanas Observatory (Chile) during 2003. We have also carried out a light-curve analysis incorporating new photometry and realistic physical parameters for the star. OGLE-TR-113b has an orbital period of only 1.43 days, a mass of 1.08±0.28 MJup, and a radius of 1.09±0.10 RJup. Similar parameters have been obtained very recently in an independent study by Bouchy et al., from observations taken a year later. The orbital period of OGLE-TR-113b, and also that of the previously announced planet OGLE-TR-56b (Porb = 1.21 days) —the first two found photometrically— are much shorter than the apparent cutoff of close-in giant planets at 3-4-day periods found from high-precision radial velocities surveys. Along with a third case reported by Bouchy et al. (OGLETR-132b, Porb = 1.69 days), these objects appear to form a new class of “very hot Jupiters” that pose very interesting questions for theoretical study. Subject headings: planetary systems — line: profiles — stars: evolution — stars: individual (OGLE-TR-113) — techniques: radial velocities California Institute of Technology, Div. of Geological & Planetary Sciences 150-21, Pasadena, CA 91125, USA; e-mail: [email protected] Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 Universidad de Concepción, Departamento de F́ısica, Astronomy Group, Casilla 160-C, Concepción, Chile Warsaw University Observatory, AL. Ujazdowskie 4, 00-478, Warsaw Poland Department of Astronomy, University of California, Berkeley, CA 94720, USA Departamento de Astronomı́a, Universidad de Chile, Casilla 36-D, Santiago, Chile Pontificia Universidad Católica de Chile, Departamento de Astronomı́a y Astrof́ısica, Casilla 306, Santiago 22, Chile