The brightest asymptotic giant branch stars in the Leo I dwarf spheroidal galaxy

Abstract

The first results of a study of the dwarf spheroidal galaxy Leo I using the new Nagoya‐South African Infrared Survey Facility (IRSF) are presented. J, H and Ks observations show that most, if not all, of at least the top magnitude of the asymptotic giant branch (AGB) in Ks is populated by carbon stars. In addition there are five very red objects which are believed to be dust-enshrouded AGB stars. One of these is, remarkably, well outside the main body of the galaxy. Three of these obscured stars and five known carbon stars show variability in