V2 in 47 Tucanae: The First Detected Dwarf Nova Outburst in the Core of a Globular Cluster

Abstract

The FOC on board the Hubble Space Telescope has been monitoring the cores of some globular clusters (GCs) in the UV since launch, to help the understanding of some peculiarities of the local stellar population. 47 Tucanae has been one of the most observed clusters, for a number of reasons. Chief among these axe its still controversial dynamical state, with two red giants being ejected from the core (Meylan 1993), the discovery of 11 millisecond pulsars (Manchester et al. 1991), the presence of the brightest among the low luminosity X-ray sources known (X0021.8-7221, Hertz & Grindlay 1983) plus some dimmer X-ray sources discovered by ROSAT (Verbunt et al. 1993), and, finally, the presence of a centrally concentrated population of blue straggler stars, discovered by the FOC team (Paresce et al. 1991).