DEEP CCD PHOTOMETRY OF THE DWARF SPHEROIDAL GALAXY LEO-II

We present a deep colour-magnitude diagram of the central 7 x 7 arcmin2 region of Leo II. The diagram shows a well-defined giant branch and a red horizontal branch, heavily populated on the red side but extending far into the blue. Having a low metallicity ([Fe/H] = -1.9), the Leo II diagram is similar to those of outer halo clusters suffering from the second-parameter syndrome. From the mean apparent magnitude of candidate RR Lyrae stars, [V(HB)] = 22.10, we estimate the distance of Leo II to be 215 kpc, a value similar to previous estimates. A number of variable-star candidates are identified and two new very red giants have been found. Comparison with the other dwarf spheroidals of the Local Group reveals that Leo II belongs to the group of four small and faint dwarf spheroidal galaxies.