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. Ruiz, A. Shporer, O. Tamuz, S. Udry, M. Zoccali, M. Kubiak, M. K. Szymanski, I. Soszynski, O. Szewczyk, K. Ulaczyk, L. Wyrzykowski
Abstract
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/NVLT/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 MJup, while its radius 1.36 +0.18 −0.09 RJup. 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.
Astronomy & Astrophysics
Volume 482, Page 299
2008 April
