Ju l 1 99 8 A Survey for Low - Surface - Brightness Galaxies Around M 31 . I . The Newly Discovered Dwarf Andromeda

We present images and a color–magnitude diagram for And V, a new dwarf spheroidal companion to M31 that was found using a digital filtering technique applied to 1550 deg of the second Palomar Sky Survey. And V resolves into stars easily in follow-up 4-m V and I-band images, from which we deduce a distance of 810 ± 45 kpc using the tip of the red giant branch method. Within the uncertainties, this distance is identical to the Population II distances for M31 and, combined with a projected separation of 112 kpc, provides strong support for a physical association between the two galaxies. There is no emission from And V detected in Hα, 1.4 GHz radio continuum, or IRAS bandpasses, and there is no young population seen in the color–magnitude diagram that might suggest that And V is an irregular. Thus, the classification as a new dwarf spheroidal member of the Local Group seems secure. With an extinction-corrected central surface brightness of 25.2 V mag/arcsec, a mean metal abundance of [Fe/H] ≈ –1.5, and no evidence for upper AGB stars, And V resembles And I & III. Subject headings: galaxies: dwarf — galaxies: individual (And V, M31) — galaxies: stellar content — galaxies: structure — Local Group — surveys — techniques: image processing