K. Vivas Abstract

The Extended View of  Pulsating Stars in the Carina Dwarf Spheroidal Galaxy

K. Vivas (Centro de Investigaciones de Astronomia) and M. Mateo

Based on observations obtained with the Blanco 4m telescope at CTIO, we report the discovery of 340 dwarf cepheids in the Carina dwarf spheroidal galaxy in an area covering the whole galaxy and extending up to a few times its tidal radius along the direction of the semi-major axis. These stars are located ~2.5 magnitudes below the horizontal branch and have very short periods (<0.1 days). Several extra-tidal dwarf cepheids were found in our survey up to a distance of ~1 deg from the center of Carina. In addition, RR Lyrae stars and anomalous cepheids, which naturally appeared as well in our observations, were identified outside the tidal radius. This confirms previous works that suggest that Carina is undergoing tidal disruption.  We found some important differences in the properties of the dwarf cepheids of Carina and those in Fornax and the LMC, which may be a reflection of metallicity spread, depth along the line of sight and/or, different evolutionary paths of the dwarf cepheid stars.