Globular Clusters Color-Magnitude Diagrams with HST

Abstract

In this paper we present the 13 B and V color-magnitude diagrams discussed by Piotto et al. in the same Procedings. The data have been collected with the WFPC2 camera on HST. We emphasize the discovery of blue horizontal branches in the two metal rich globular clusters NGC 6388 and NGC 6441, and the four-mode HB of NGC 2808. The significance of the gaps in the HB of NGC 2808 is also assesed.