OGLE-TR-211 - a new transiting inflated hot Jupiter from the OGLE survey and ESO LP666 spectroscopic follow-up program

A. UDALSKI; F. PONT; D. NAEF; C. MELO; F. BOUCHY; N. C. SANTOS; C. MOUTOU; R. F. DÍAZ; W. GIEREN; M. GILLON; S. HOYER; M. MAYOR; T. MAZEH; D. MINNITI; G. PIETRZYNSKI; D. QUELOZ; S. RAMÍREZ; M. T. RUÍZ; A. SHPORER; O. TAMUZ; S. UDRY; M. ZOCCALI; M. KUBIAK; M. K. SZYMANSKI; I. SOSZYNSKI; O. SZEWCZYK; K. ULACZYK; L. WYRZYKOWSKI

ASTRONOMY AND ASTROPHYSICS

EDP Sciences

Lugar: Les Ulis, Francia; Año: 2008 vol. 482 p. 299 - 304

0004-6361

We present results of the photometric campaign for planetary and low-luminosity object transits conducted by the OGLE survey in the 2005 season (Campaign #5). About twenty of the most promising candidates discovered in these data were subsequently verified spectroscopically with the VLT/FLAMES spectrograph. One of the candidates, OGLE-TR-211, reveals clear changes of radial velocity with a small amplitude of 82 m/s, varying in phase with photometric transit ephemeris. Further analysis confirms the planetary nature of this system. Follow-up precise photometry of OGLE-TR-211 with VLT/FORS, together with radial velocity spectroscopy, supplemented with high-resolution, high S/N VLT/UVES spectra allowed us to derive parameters of the planet and host star. OGLE-TR-211b is a hot Jupiter orbiting an F7-8 spectral type dwarf star with a period of 3.68 days. The mass of the planet is equal to 1.03±0.20 M_Jup, while its radius 1.36+0.18-0.09 R_Jup. The radius is about 20% larger than the typical radius of hot Jupiters of similar mass. OGLE-TR-211b is, then, another example of inflated hot Jupiters - a small group of seven exoplanets with large radii and unusually low densities - objects that are a challenge to the current models of exoplanets.