Letter to the Editor

Spectral types of planetary host star candidates: Two new transiting planets?

¹ Institut für Astronomie und Astrophysik, Abt. Astronomie, Sand 1, Universität Tübingen, 72076 Tübingen, Germany
² Dr. Remeis-Sternwarte, Sternwartstraße 7, 96049 Bamberg, Germany
³ Dept. of Physics & Astronomy, The University of Georgia, Athens, GA 30602-2451, USA
⁴ Institut für Astronomie und Astrophysik, Abt. Computational Physics, Auf der Morgenstelle 10, Universität Tübingen, 72076 Tübingen, Germany

Corresponding author: S. Dreizler, dreizler@astro.uni-tuebingen.de

Received: 7 June 2002
Accepted: 9 July 2002

Abstract

Recently, 46 low-luminosity object transits were reported from the Optical Gravitational Lensing Experiment. Our follow-up spectroscopy of the 16 most promising candidates provides a spectral classification of the primary. Together with the radius ratio from the transit measurements, we derived the radii of the low-luminosity companions. This allows to examine the possible sub-stellar nature of these objects. Fourteen of them can be clearly identified as low-mass stars. Two objects, OGLE-TR-03 and OGLE-TR-10 have companions with radii of 0.15 which is very similar to the radius of the transiting planet HD 209458 B. The planetary nature of these two objects should therefore be confirmed by dynamical mass determinations.