NGC 4157 | |
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![]() NGC 4157 and superimposed bright star SAO 28277 | |
Observation data (J2000 epoch) | |
Constellation | Ursa Major |
Right ascension | 12h 11m 04.4s [1] |
Declination | +50° 29′ 05″ [1] |
Redshift | 0.002572 ± 0.000005 [1] |
Heliocentric radial velocity | 771 ± 1 km/s [1] |
Distance | 55.8 ± 10 Mly (17.1 ± 3.1 Mpc) [1] |
Apparent magnitude (V) | 11.3 [2] |
Characteristics | |
Type | SAB(s)b? [1] |
Apparent size (V) | 7.95′ × 1.06′ [1] |
Notable features | Edge-on galaxy |
Other designations | |
UGC 7183, MCG +09-20-106, CGCG 269-038, IRAS 12085+5045, PGC 38795, 6C B120833.1+504537 |
NGC 4157 is a spiral galaxy in the constellation Ursa Major. The galaxy lies about 55 million light years away from Earth, which means, given its apparent dimensions, that NGC 4157 is approximately 125,000 light years across. [1] It was discovered by William Herschel on March 9, 1788. [3]
NGC 4157 seen nearly edge-on, with an inclination of 84° based on CO imaging. [4] The total stellar mass of NGC 4157 is (2.92±0.04)×1010 M☉ , [5] while the dust mass is estimated to be 2.1×107 M☉. [6] The hydrogen disk of NGC 4157 is symmetric and slightly wrapped, indicating no strong interaction with other galaxies, and extends to twice the size of the optical disk. [7] The total HI mass in the galaxy is estimated to be 109.72 M☉. [7]
The star formation rate of the galaxy is 1.76±0.18 M☉ per year. [5] A star formation area is visible beyond the end of the optical disk and is also visible in X-ray and ultraviolet imaging. It could probably be the result of a recent accretion. [8]
The galaxy has radio emission extending above and below the optical disk, indicating the presence of a radio halo. There is also radio emission extending southwards from the north-eastern end of the disk. [6]
Three supernovae have been observed in NGC 4157: SN 1937A (mag. 16.2), SN 1955A (mag. 16), and SN 2003J. [9] SN 2003J was a type II supernova which had an apparent magnitude of 16.7 upon discovery. [10] [11]
NGC 4157 is the foremost galaxy of the NGC 4157 Group. Other members of the group include NGC 4085, NGC 4088, UGC 6992, and UGC 7176. [12] UGC 7176 is a companion of NGC 4157, lying 12 arcminutes away. [6] The group is part of the Ursa Major Cluster, a large association of mostly spiral galaxies lying north of the Virgo Cluster, that is part of the Local Supercluster. NGC 4157 is one of the dominant galaxies in the cluster, along with NGC 3769, NGC 3877, NGC 3992, NGC 4111, NGC 4217 and NGC 4346. [12]
Messier 108 is a barred spiral galaxy about 28 million light-years away from Earth in the northern constellation Ursa Major. It was discovered by Pierre Méchain in 1781 or 1782. From the Earth, this galaxy is seen almost edge-on.
NGC 6946, sometimes referred to as the Fireworks Galaxy, is a face-on intermediate spiral galaxy with a small bright nucleus, whose location in the sky straddles the boundary between the northern constellations of Cepheus and Cygnus. Its distance from Earth is about 25.2 million light-years or 7.72 megaparsecs, similar to the distance of M101 in the constellation Ursa Major. Both were once considered to be part of the Local Group, but are now known to be among the dozen bright spiral galaxies near the Milky Way but beyond the confines of the Local Group. NGC 6946 lies within the Virgo Supercluster.
NGC 1566, sometimes known as the Spanish Dancer, is an intermediate spiral galaxy in the constellation Dorado, positioned about 3.5° to the south of the star Gamma Doradus. It was discovered on May 28, 1826 by Scottish astronomer James Dunlop. At 10th magnitude, it requires a telescope to view. The distance to this galaxy remains elusive, with measurements ranging from 6 Mpc up to 21 Mpc.
NGC 5643 is an intermediate spiral galaxy in the constellation Lupus. Based on the tip of the red-giant branch distance indicator, it is located at a distance of about 40 million light-years. NGC 5643 has an active galactic nucleus and is a type II Seyfert galaxy.
NGC 2782 is a peculiar spiral galaxy that formed after a galaxy merger in the constellation Lynx. The galaxy lies 75 million light years away from Earth, which means, given its apparent dimensions, that NGC 2782 is approximately 100,000 light years across. NGC 2782 has an active galactic nucleus and it is a starburst and a type 1 Seyfert galaxy. NGC 2782 is mentioned in the Atlas of Peculiar Galaxies in the category galaxies with adjacent loops.
NGC 4111 is a lenticular galaxy in the constellation Canes Venatici. It is located at a distance of circa 50 million light-years from Earth, which, given its apparent dimensions, means that NGC 4111 is about 55,000 light-years across. It was discovered by William Herschel in 1788. NGC 4111 possesses both thin and thick discs.
NGC 3941 is a barred lenticular galaxy located in the constellation Ursa Major. It is located at a distance of circa 40 million light years from Earth, which, given its apparent dimensions, means that NGC 3941 is about 40,000 light years across. It was discovered by William Herschel in 1787.
NGC 4026 is an edge-on lenticular galaxy in the constellation Ursa Major. It is located at a distance of circa 50 million light years from Earth, which, given its apparent dimensions, means that NGC 4026 is about 80,000 light years across. It was discovered by William Herschel on April 12, 1789.
NGC 3631 is a spiral galaxy located in the constellation Ursa Major. It is located at a distance of about 35 million light years from Earth, which, given its apparent dimensions, means that NGC 3631 is about 60,000 light years across. It was discovered by William Herschel on April 14, 1789. It is a grand design spiral galaxy seen face on.
NGC 5084 is a lenticular galaxy in the constellation of Virgo. It is located at a distance of about 80 million light years from Earth, which, given its apparent dimensions, means that NGC 5084 is at least 200,000 light years across. It is one of the largest and most massive galaxies in the Virgo Supercluster. William Herschel discovered it on March 10, 1785. It is a member of the NGC 5084 Group of galaxies, which is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. The galaxy is seen nearly edge-on, with inclination 86°, and features a warped disk and large quantities of HI gas extending along the disk, probably accumulated after multiple accretions of smaller galaxies.
NGC 7213 is a lenticular galaxy located in the constellation Grus. It is located at a distance of circa 70 million light-years from Earth, which, given its apparent dimensions, means that NGC 7213 is about 75,000 light-years across. It was discovered by John Herschel on September 30, 1834. It is an active galaxy with characteristics between a type I Seyfert galaxy and LINER.
NGC 5965 is a spiral galaxy located in the constellation Draco. It is located at a distance of circa 150 million light years from Earth, which, given its apparent dimensions, means that NGC 5965 is about 260,000 light years across. It was discovered by William Herschel on May 5, 1788.
NGC 1380 is a lenticular galaxy located in the constellation Fornax. It is located at a distance of circa 60 million light years from Earth, which, given its apparent dimensions, means that NGC 1380 is about 85,000 light years across. It was discovered by James Dunlop on September 2, 1826. It is a member of the Fornax Cluster.
NGC 1386 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of circa 53 million light years from Earth, which, given its apparent dimensions, means that NGC 1386 is about 50,000 light years across. It is a Seyfert galaxy, the only one in Fornax Cluster.
NGC 3665 is a lenticular galaxy located in the constellation Ursa Major. It is located at a distance of circa 85 million light-years from Earth, which, given its apparent dimensions, means that NGC 3665 is about 85,000 light years across. It was discovered by William Herschel on March 23, 1789.
NGC 931 is a spiral galaxy located in the constellation Triangulum. It is located at a distance of circa 200 million light-years from Earth, which, given its apparent dimensions, means that NGC 931 is about 200,000 light years across. It was discovered by Heinrich d'Arrest on September 26, 1865. It is classified as a Seyfert galaxy.
NGC 3656 is a peculiar galaxy formed by the collision of two galaxies in the constellation of Ursa Major. It is located about 135 million light years away from Earth, which means, given its apparent dimensions, that NGC 3656 is approximately 70,000 light years across. It was discovered by William Herschel on April 14, 1789.
NGC 3044 is a barred spiral galaxy in the equatorial constellation of Sextans. It was discovered on December 13, 1784, by German-born English astronomer William Herschel. In 1888, Danish astronomer J. L. E. Dreyer described it as "very faint, very large, very much extended 122°". It is located at an estimated distance of 67 million light years. In the B band of the UBV photometric system, the galaxy spans 4.70′ by 0.80′ with the major axis aligned along a position angle of 113°. It is a relatively isolated galaxy with no nearby companions. R. B. Tully in 1988 assigned it as a member of the widely displaced Leo Cloud.
NGC 3448 is an irregular galaxy in the constellation Ursa Major. The galaxy lies about 75 million light years away from Earth, which means, given its apparent dimensions, that NGC 3448 is approximately 125,000 light years across. It was discovered by William Herschel on April 17, 1789.
NGC 4096 is a spiral galaxy in the constellation Ursa Major. The galaxy lies about 35 million light years away from Earth, which means, given its apparent dimensions, that NGC 4096 is approximately 80,000 light years across. It was discovered by William Herschel on March 9, 1788.