The globular cluster Messier 79 (NGC 1904) appears in the constellation Lepus - an unusual place for such an object, in the celestial hemisphere opposite the galactic center.
M 79 was discovered by Pierre Mechain in October 1780, who reported it to his friend and colleague Charles Messier. It was first resolved into stars by William Herschel in 1784.
Messier 79 is a bright magnitude 7.7 globular with a dense core, surrounded by a 9.6' diameter halo. Dozens of stars can be resolved across the cluster in a 8-inch telescope. It is a beautiful globular at an unusual location in the sky: most globulars are grouped around the galactic center, but this one is situated on the opposite side of the Milky Way's central bulge from our solar system.
Messier 79 estimated to be about 40,000 light years from us, and 60,000 light years from the Galactic Center. At this distance, M 79's angular diameter corresponds to a linear diameter of 18 light years. The cluster contains only 7 known variable stars, and is receding from us at 200 km/sec.
In 2003, it was found that M 79 may not be native to the Milky Way galaxy, but instead part of the Canis Major dwarf galaxy, which is currently experiencing a very close encounter with the Milky Way. Along with M 79, three other globulars are suspected to have immigrated from the Canis Major dwarf: NGC 1851, NGC 2298, and NGC 2808. This is a contentious subject, as astronomers are still debating the nature of the Canis Major dwarf galaxy.
The double star ADS 3954 (magnitude 5.5 and 7.0, separation 3") appears about 1/2° southwest of M 79.