[en] Transiting planets are essential to study the structure and evolution of extra-solar planets. For that purpose, it is important to measure precisely the radius of these planets. Here we report new high-accuracy photometry of the transits of OGLE-TR-10 and OGLE-TR-56 with VLT/FORS1. One transit of each object was covered in Bessel V and R filters, and treated with the deconvolution-based photometry algorithm DECPHOT, to ensure accurate millimagnitude light curves. Together with earlier spectroscopic measurements, the data imply a radius of 1.22{[SUP]+0.12[/SUP][SUB]-0.07[/SUB]} R[SUB]J[/SUB] for OGLE-TR-10b and 1.30 ± 0.05 R[SUB]J[/SUB] for OGLE-TR-56b. A re-analysis of the original OGLE photometry resolves an earlier discrepancy about the radius of OGLE-TR-10. The transit of OGLE-TR-56 is almost grazing, so that small systematics in the photometry can cause large changes in the derived radius. Our study confirms both planets as inflated hot Jupiters, with large radii comparable to that of HD 209458b and at least two other recently discovered transiting gas giants. Based on data collected with the FORS1 imager at the VLT-Kueyen telescope (Paranal Observatory, ESO, Chile) in the programme 177.C-0666E.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Pont, F.; Observatoire de Genève, 51 chemin des Maillettes, 1290 Sauverny, Switzerland
Moutou, C.; Laboratoire d'Astrophysique de Marseille, Traverse du Siphon, BP 8, Les Trois Lucs, 13376 Marseille Cedex 12, France
Gillon, Michaël ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique et traitement de l'image
Bouchy, F.; Observatoire de Haute-Provence, 04870 St-Michel l'Observatoire, France ; Institut d'Astrophysique de Paris, 98bis Bd. Arago, 75014 Paris, France
Fernandes, J. M.; Grupo de Astrofísica UC, Observatório Astronómico da Universidade de Coimbra, Santa Clara, Coimbra, Portugal
Gieren, W.; Departamento de Fisica, Astronomy Group, Universidad de Concepción, Casilla 160-C, Concepción, Chile
Mayor, M.; Observatoire de Genève, 51 chemin des Maillettes, 1290 Sauverny, Switzerland
Mazeh, T.; School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
Minniti, D.; Departmento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile
Melo, C.; European Southern Observatory, Casilla 19001, Santiago 19, Chile
Naef, D.; European Southern Observatory, Casilla 19001, Santiago 19, Chile
Pietrzynski, G.; Departamento de Fisica, Astronomy Group, Universidad de Concepción, Casilla 160-C, Concepción, Chile ; Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warsaw, Poland
Queloz, D.; Observatoire de Genève, 51 chemin des Maillettes, 1290 Sauverny, Switzerland
Ruiz, M. T.; Department of Astronomy, Universidad de Chile, Santiago, Chile
Santos, N. C.; Observatoire de Genève, 51 chemin des Maillettes, 1290 Sauverny, Switzerland ; Centro de Astronomia e Astrofísica da Universidade de Lisboa, Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal ; Centro de Geofisica de Évora, Rua Romão Ramalho 59, 7002-554 Évora, Portugal
Udry, S.; Observatoire de Genève, 51 chemin des Maillettes, 1290 Sauverny, Switzerland
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