M101 Group
Encyclopedia
The M101 Group is a loose group of galaxies located in Ursa Major
. The group is named after the brightest galaxy in the group, the Pinwheel Galaxy
(M101). Most of the other members of the group are companions of the Pinwheel Galaxy. The group itself is one of many located within the Virgo Supercluster
(i.e. the Local Supercluster).
Other possible members galaxies (galaxies listed in only one or two of the lists from the above references) include the irregular galaxies NGC 5238 and UGC 8508.
, which includes the Whirlpool Galaxy (M51)
and the Sunflower Galaxy (M63)
, is located to the southeast of the M101 Group, and the NGC 5866 Group
is located to the northwest. The distances to these three groups (as determined from the distances to the individual member galaxies) are similar, which suggests that the M51 Group, the M101 Group, and the NGC 5866 Group are actually part of a single large, loose, elongated group. However, most group identification methods (including those used by the references cited above) identify these three groups as separate entities.
Ursa Major
Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April...
. The group is named after the brightest galaxy in the group, the Pinwheel Galaxy
Pinwheel Galaxy
The Pinwheel Galaxy is a face-on spiral galaxy distanced 21 million light-years away in the constellation Ursa Major, first discovered by Pierre Méchain on March 27, 1781, and communicated to Charles Messier who verified its position for inclusion in the Messier Catalogue as one of its final...
(M101). Most of the other members of the group are companions of the Pinwheel Galaxy. The group itself is one of many located within the Virgo Supercluster
Virgo Supercluster
The Virgo Supercluster or Local Supercluster is the irregular supercluster that contains the Virgo Cluster in addition to the Local Group, which in turn contains the Milky Way and Andromeda galaxies. At least 100 galaxy groups and clusters are located within its diameter of 33 megaparsecs...
(i.e. the Local Supercluster).
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) Catalog, and the three group lists created from the Nearby Optical Galaxy sample of Giuricin et al.| Name | Type | R.A. Right ascension Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:... (J2000) |
Dec. Declination In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and... (J2000) |
Redshift Redshift In physics , redshift happens when light seen coming from an object is proportionally increased in wavelength, or shifted to the red end of the spectrum... (km/s Second The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock.... ) |
Apparent Magnitude Apparent magnitude The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere... |
|---|---|---|---|---|---|
| Pinwheel Galaxy (M101) Pinwheel Galaxy The Pinwheel Galaxy is a face-on spiral galaxy distanced 21 million light-years away in the constellation Ursa Major, first discovered by Pierre Méchain on March 27, 1781, and communicated to Charles Messier who verified its position for inclusion in the Messier Catalogue as one of its final... |
SAB(rs)cd | 241 ± 2 | 8.3 | ||
| NGC 5204 | SA(s)m | 201 ± 1 | 11.7 | ||
| NGC 5474 NGC 5474 NGC 5474 is a peculiar dwarf galaxy in the constellation Ursa Major. It is one of several companion galaxies of the Pinwheel Galaxy , a grand-design spiral galaxy.... |
SA(s)cd pec | 273 ± 9 | 11.3 | ||
| NGC 5477 | SA(s)m | 304 ± 5 | 14.4 | ||
| NGC 5585 | SAB(s)d | 305 ± 3 | 11.2 | ||
| UGC 8837 | IB(s)m | 144 ± 3 | 13.8 | ||
| UGC 9405 | Im | 222 ± 6 | 17 | ||
Other possible members galaxies (galaxies listed in only one or two of the lists from the above references) include the irregular galaxies NGC 5238 and UGC 8508.
Nearby groups
The M51 GroupM51 Group
The M51 Group is a group of galaxies located in Canes Venatici. The group is named after the brightest galaxy in the group, the Whirlpool Galaxy...
, which includes the Whirlpool Galaxy (M51)
Whirlpool Galaxy
The Whirlpool Galaxy is an interacting grand-design spiral galaxy that is estimated to be 23 ± 4 million light-years from the Milky Way Galaxy. in the constellation Canes Venatici...
and the Sunflower Galaxy (M63)
Sunflower Galaxy
The Sunflower Galaxy is a spiral galaxy in the constellation Canes Venatici consisting of a central disc surrounded by many short spiral arm segments...
, is located to the southeast of the M101 Group, and the NGC 5866 Group
NGC 5866 Group
The NGC 5866 Group is a small group of galaxies located in the constellation Draco. The group is named after NGC 5866, the galaxy with the highest apparent magnitude in the group, although some galaxy group catalogs list NGC 5907 as the brightest member....
is located to the northwest. The distances to these three groups (as determined from the distances to the individual member galaxies) are similar, which suggests that the M51 Group, the M101 Group, and the NGC 5866 Group are actually part of a single large, loose, elongated group. However, most group identification methods (including those used by the references cited above) identify these three groups as separate entities.