Doppler follow-up of OGLE transiting companions in the Galactic bulge^*

¹ Laboratoire d'Astrophysique de Marseille, Traverse du Siphon, BP 8, 13376 Marseille Cedex 12, France e-mail: Francois.Bouchy@oamp.fr
² Observatoire de Genève, 51 ch. des Maillettes, 1290 Sauverny, Switzerland
³ European Southern Observatory, Casilla 19001, Santiago 19, Chile
⁴ Centro de Astronomia e Astrofísica da Universidade de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal

Received: 23 July 2004
Accepted: 13 October 2004

Abstract

Two years ago, the OGLE-III survey (Optical Gravitational Lensing Experiment) announced the detection of 54 short period multi-transiting objects in the Galactic bulge (Udalski et al. [CITE],b). Some of these objects were considered to be potential hot Jupiters. In order to determine the true nature of these objects and to characterize their actual mass, we conducted a radial velocity follow-up of 18 of the smallest transiting candidates. We describe here our procedure and report the characterization of 8 low-mass star-transiting companions, 2 grazing eclipsing binaries, 2 triple systems, 1 confirmed exoplanet (OGLE-TR-56b), 1 possible exoplanet (OGLE-TR-10b), 1 clear false positive and 3 unsolved cases. The variety of cases encountered in our follow-up covers a large part of the possible scenarios occurring in the search for planetary transits. As a by-product our program yields precise masses and radii of low mass stars.