Carbon Stars in the Sagittarius Dwarf Galaxy

Abstract

Coordinates are listed for 26 carbon stars which are radial velocity members of the Sagittarius Dwarf Galaxy (SDG). Their near-infrared properties indicate that most are on an extended Asymptotic Giant Branch (AGB), and the total number of such stars in the SDG is estimated at about 100. At least one-third of the C stars studied are large amplitude, i.e. Mira, variables; these are the first Miras to be found in a dSph galaxy. Surprisingly, the most luminous C star is not a Mira, but a low amplitude variable.A comparison of the properties of C stars in the Bulge and in the SDG indicates that the two groups cannot be drawn from the same population. It is therefore highly unlikely that the Bulge C stars are, contrary to previous suggestions, related in any way to the SDG.