High resolution spectroscopy of stars with transiting planets

The cases of OGLE-TR-10, 56, 111, 113, and TrES-1

¹ Centro de Astronomia e Astrofísica da Universidade de Lisboa, Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal e-mail: nuno@oal.ul.pt
² Observatoire de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
³ European Southern Observatory, Casilla 19001, Santiago 19, Chile
⁴ Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain
⁵ Laboratoire d'Astrophysique de Marseille, Traverse du Siphon, 13013 Marseille, France
⁶ Observatoire de Haute Provence, 04870 St. Michel l'Observatoire, France
⁷ Observatoire de la Côte d'Azur, BP 4229, 06304 Nice Cedex 04, France

Received: 24 November 2005
Accepted: 21 December 2005

Abstract

Context.During the past years photometric surveys, later complemented by follow-up radial-velocity measurements, have revealed the presence of several new extra-solar transiting planets, in very short-period orbits. Many of the host stars are extremely faint (), making high-precision spectroscopic measurements challenging.

Aims.We used the UVES spectrograph (VLT-UT2 telescope) to obtain high-resolution spectra of 5 stars hosting transiting planets, namely for OGLE-TR-10, 56, 111, 113, and TrES-1. The immediate objective is to derive accurate stellar parameters and chemical abundances.

Methods.The stellar parameters were derived from an LTE analysis of a set of and lines.

Results.Complementing the spectroscopic information with photometric transit curves and radial-velocity data from the literature, we then refined the stellar and planetary radii and masses. The obtained data were also used to study the relation between the stellar metallicity and orbital period of the planets.