Red supergiant stars in blue compact dwarf galaxies: The case of Tol 0610-387^*

¹ European Southern Observatory, Karl Schwarzchild str. 2, 85748 Garching, Germany
² Observatoire de Marseille and Institut Cassendi, 2 place Le Verrier, 13004 Marseille, France
³ LAEFF-INTA, Apdo. 50727, 28080 Madrid, Spain
⁴ Dept. of Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street Urbana, Ill 61801, USA
⁵ Institut d'Astrophysique de Paris, 98 bis Bd. Arago, 75014 Paris, France

Corresponding author: V. Doublier, vdoublie@eso.org

Received: 30 March 1999
Accepted: 1 March 2001

Abstract

We have investigated the stellar content of the blue compact dwarf galaxies (BCDG) Tol 0610-387 by combining near infrared and optical images, complemented by spectroscopic data. The color maps, combined with the Hα image allowed us to identify clusters possibly dominated by red supergiant stars (RSG) associated with the current ongoing starburst episode. The analysis shows that the local colors and Hα emission, when compared with the predictions from population synthesis models, are consistent with an aging stellar population of around 10-15 Myrs dominated by red supergiant stars. This galaxy could therefore become a preferred target for the spectroscopic confirmation and analysis of its RSG population. Since the presence of such stars in BCDGs is seldom observed, we discuss the implications of RSG detection for the study of the starburst dynamics and evolution.