The M109 Group (also known as the NGC 3992 Group or Ursa Major cloud) is a group of galaxies about 55 million

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s awayThe Ursa Major Groups
/ref> in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Ursa Major. The group is named after the brightest galaxy within the group, the

spiral galaxy Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''M109 The M109 is an American 155 mm turreted Self-propelled artillery, self-propelled howitzer, first introduced in the early 1960s to replace the M44 self propelled howitzer, M44. It has been upgraded a number of times, most recently to the M109A7. T ...

Members

The table below lists galaxies that have been consistently identified as group members in the Nearby Galaxies Catalog, the survey of Fouque et al., the Lyons Groups of Galaxies (LGG) Catalogue, and the three group lists created from the Nearby Optical Galaxy sample of Giuricin et al. Galaxies frequently but not consistently listed as group members in the above references (i.e. galaxies listed in four of the above lists) include

NGC 3631 NGC 3631 is a spiral galaxy located in the constellation Ursa Major. It is located at a distance of circa 35 million light years from Earth, which, given its apparent dimensions, means that NGC 3631 is about 60,000 light years across. It was disco ...

, NGC 3657, NGC 3733, NGC 3756, NGC 3850, NGC 3898, NGC 3985, NGC 3990, NGC 3998,

NGC 4217 NGC 4217 is an edge-on spiral galaxy which lies approximately 60 million light-years (18 million parsecs) away in the constellation of Canes Venatici. It is a possible companion galaxy to Messier 106 (also known as NGC 4258). Gallery Dust fil ...

, NGC 4220,

UGC 6773 UGC may refer to: Science and technology * Universal gravitational constant G, in physics * Uppsala General Catalogue, an astronomical catalogue of galaxies * UGC, a codon for cysteine * Unique games conjecture, a conjecture in computational com ...

, UGC 6802, UGC 6816, UGC 6922, and

UGC 6969 UGC may refer to: Science and technology * Universal gravitational constant G, in physics * Uppsala General Catalogue, an astronomical catalogue of galaxies * UGC, a codon for cysteine * Unique games conjecture, a conjecture in computational comp ...

. The exact membership and the exact number of galaxies in the group is somewhat uncertain. Fouque et al. lists these galaxies as two separate groups named ''Ursa Major I North'' and ''Ursa Major I South'', both of which were used to compile the above table. Most other references, however, identify this as a single group, as is specifically noted in the LGG Catalogue.

References

{{reflist Ursa Major Cluster Ursa Major (constellation) Virgo Supercluster