Sombrero Galaxy lies within a complex, filament-like cloud of galaxies that extends to the south of the Virgo Cluster. However, it is unclear whether it is part of a formal galaxy group. Hierarchical methods for identifying groups, which determine group membership by considering whether individual galaxies belong to a larger aggregate of galaxies, typically produce results showing that the Sombrero Galaxy is part of a group that includes NGC 4487, NGC 4504, NGC 4802, UGCA 289, and possibly a few other galaxies. However, results that rely on the percolation method (i.e. the "friends-of-friends" method), which links individual galaxies together to determine group membership, indicate that either the Sombrero Galaxy is not in a group or that it may be only part of a galaxy pair with UGCA 287. Besides that, M104 is also accompanied by an ultra-compact dwarf galaxy, discovered in 2009, with an absolute magnitude of −12.3, an effective radius of just , and a mass of 3.3× Amateur astronomy The Sombrero Galaxy is 11.5° west of Spica and 5.5° north-east of Eta Corvi. Although it is visible with 7×35 binoculars or a amateur telescope, an telescope is needed to distinguish the bulge from the disk, and a 10- or 12-inch (250 or 300 mm) telescope to see the dark dust lane. See also List of Messier objects Lists of astronomical objects NGC 1291, a galaxy with an outer dust ring NGC 4725, a similar galaxy with an extended dust ring NGC 6027a, a member of Seyfert's Sextet with a very similar dust ring structure NGC 7742, a spiral galaxy with a similar dust ring NGC 7814, a galaxy sometimes referred to as "the little sombrero" Ring galaxy Messier object New General Catalogue Notes References External links Hubble Mosaic of the Majestic Sombrero Galaxy (ESA) HubbleSite: The Majestic Sombrero Galaxy (M104) M104, the Sombrero Galaxy (NightSkyInfo.com) Messier 104 (SEDS) Sombrero Galaxy: A Great Observatories View M104 The Sombrero Galaxy Sombrero Galaxy (Messier 104) at Constellation Guide Elliptical galaxies Spiral galaxies LINER galaxies Virgo (constellation) Messier objects NGC objects 42407 17810511 Discoveries by Pierre Méchain Peculiar galaxies UGCA objects