| Abstract | H I measurements of a new dwarf galaxy in the Local Group, LGS 3, are reported. LGS 3 has a heliocentric velocity of -280 km/s and is resolved into stars on the Palomar Sky Survey prints. It is probably a satellite of M33. In that case, the absolute photographic magnitude of LGS 3 is about -9.0, making it one of the faintest irregular galaxies known. Its hydrogen mass is only 200,000 solar masses, one of the smallest reported for a galaxy. Other optical and H I properties are discussed. Of the five low-surface-brightness galaxies reported by Kowal, Lo, and Sargent (1978), only one other galaxy, LGS 1, was detected with a heliocentric velocity of 3695 km/s. Its absolute photographic magnitude is -17.1, and thus LGS 1 is not a bona fide dwarf galaxy despite its very low surface brightness. H I upper limits are presented for the other LGS galaxies and two dwarf spheroidal companions of M31. The implications of these limits are discussed. |
