EDP Sciences
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Volume 482, Number 1, April IV 2008
Page(s) 299 - 304
Section Planets and planetary systems
DOI http://dx.doi.org/10.1051/0004-6361:20079143
Published online 25 February 2008

A&A 482, 299-304 (2008)
DOI: 10.1051/0004-6361:20079143

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

A. Udalski1, 2, F. Pont3, D. Naef4, C. Melo4, F. Bouchy5, N. C. Santos6, C. Moutou7, R. F. Díaz8, W. Gieren9, M. Gillon3, S. Hoyer10, M. Mayor3, T. Mazeh11, D. Minniti12, G. Pietrzynski1, 2, 9, D. Queloz3, S. Ramirez5, M. T. Ruiz10, A. Shporer11, O. Tamuz11, S. Udry3, M. Zoccali12, M. Kubiak1, 2, M. K. Szymanski1, 2, I. Soszynski1, 2, O. Szewczyk1, 2, 9, K. Ulaczyk1, 2, and L. Wyrzykowski2, 13

1  Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warsaw, Poland
    e-mail: udalski@astrouw.edu.pl
2  The OGLE Team
3  Observatoire de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
4  European Southern Observatory, Casilla 19001, Santiago 19, Chile
5  Institut d'Astrophysique de Paris, 98bis Bd Arago, 75014 Paris, France
6  Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
7  Laboratoire d'Astrophysique de Marseille, Traverse du Siphon, BP 8, Les Trois Lucs, 13376 Marseille Cedex 12, France
8  Instituto de Astronomia y Física del Espacio (CONICET-UBA), Buenos Aires, Argentina
9  Departamento de Fisica, Astronomy Group, Universidad de Concepción, Casilla 160-C, Concepción, Chile
10  Department of Astronomy, Universidad de Chile, Santiago, Chile
11  School of Physics and Astronomy, R. and B. Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
12  Departmento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
13  Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK

(Received 26 November 2007 / Accepted 4 February 2008)

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$\pm$0.20 $M_{\rm Jup}$, while its radius ${\rm 1.36}^{+0.18}_{-0.09}$ $R_{\rm Jup}$. 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.

Key words: planetary systems -- stars: individual: OGLE-TR-211

© ESO 2008