(a) Identification of the HST field used in this study on a deep color image of the Virgo core by Mihos et al. (2005). North is up and east to the left. The white cross indicates the number density center of Virgo cluster members given by Binggeli et al. (1987). (b) A color map of the HST field. A dwarf spheroidal galaxy, dSph-D07, investigated by Durrell et al. (2007) is marked by a white circle and the new Virgo UFD1 is indicated by red square. (c) A 10'' × 10'' section of the HST field of Virgo UFD1. The dashed circle indicates the tidal radius of Virgo UFD1. Note that most resolved stars are red giants in the galaxy.