GLOBULAR-CLUSTER-1 AND GLOBULAR-CLUSTER-3 IN THE FORNAX DWARF GALAXY

We have performed photometric CCD observations of the giant and horizo ntal branches of the globular cluster 1, and of the giant branch of cl uster 3, in the Fornax dwarf spheroidal galaxy. The observations were performed in the V and I standard broad-band filters as well as throug h two narrow-band filters especially designed to distinguish between c arbon and M type stars. The AGE is richly populated with carbon-rich s tars, and all of them are considerably below the theoretical lower lum inosity limit for such stars. If the Fornax clusters are interpreted a s resembling an earlier epoch of the Galactic globular clusters, the l ow luminosities of the carbon stars therefore point to a larger role o f the low-mass stars in the chemical enrichment of our Galaxy. The gia nt branches of the Fornax clusters are much broader than canonical gia nt branches in Galactic globulars, and the AGE is more well populated. We suggest that the morphology and stellar population of the giant br anches indicate that the dwarf galaxies are approximate to 3 Gyr young er than the Galactic halo which in turn seems to be approximate to 3 G yr younger than the Galactic globular clusters.