NGC 2857 | |
---|---|
Observation data (J2000 epoch) | |
Constellation | Ursa Major [1] |
Right ascension | 09h 24m 37.698s [2] |
Declination | +49° 21′ 25.69″ [2] |
Redshift | 0.016301 ± 0.000023 [3] |
Helio radial velocity | 4887 ± 7 km/s [3] |
Galactocentric velocity | 4917 ± 7 km/s [3] |
Distance | 69.050 ± 00 kpc (225.21 ± 0.00 kly)h−1 0.73 [3] |
Apparent magnitude (V) | 12.27 [2] |
Apparent magnitude (B) | 12.90 [2] |
Absolute magnitude (V) | -21.92 ± 0.22 [3] |
Characteristics | |
Type | SA(s)c [3] |
Size | 125,000 [1] |
Apparent size (V) | 1.70′ × 1.43′ [3] |
Other designations | |
NGC 2857, Arp 1, APG 1, PGC 26666, UGC 5000 |
NGC 2857 (also known as Arp 1 and PGC 26666) is a spiral galaxy in the constellation Ursa Major. It was discovered on January 9, 1856, by R. J. Mitchell. [1]
NGC 2857 is the first object in Halton Arp's Atlas of Peculiar Galaxies, and one of six Arp objects in the 'Low Surface Brightness Galaxies' section. The other five low surface brightness galaxies are Arp 2 (UGC 10310), Arp 3, Arp 4, Arp 5 (NGC 3664), and Arp 6 (NGC 2537). [4]
On October 10, 2012, supernova SN 2012fg was observed in NGC 2857 by the MASTER-Kislovodsk auto-detection system. [5] [6] Its absolute magnitude was calculated to be -19.8. [7] The spectrum of SN 2012fg was recorded and analyzed by multiple teams of scientists as it changed rapidly in the days following its detection. [8] [9]
Centaurus A is a galaxy in the constellation of Centaurus. It was discovered in 1826 by Scottish astronomer James Dunlop from his home in Parramatta, in New South Wales, Australia. There is considerable debate in the literature regarding the galaxy's fundamental properties such as its Hubble type and distance. NGC 5128 is one of the closest radio galaxies to Earth, so its active galactic nucleus has been extensively studied by professional astronomers. The galaxy is also the fifth-brightest in the sky, making it an ideal amateur astronomy target. It is only visible from the southern hemisphere and low northern latitudes.
NGC 300 (also known as Caldwell 70) is a spiral galaxy in the constellation Sculptor. It is one of the closest galaxies to the Local Group, and probably lies between the latter and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group. It is inclined at an angle of 42° when viewed from Earth and shares many characteristics of the Triangulum Galaxy. It is 94,000 light-years in diameter, somewhat smaller than the Milky Way, and has an estimated mass of (2.9 ± 0.2) × 1010M☉.
NGC 3184, the Little Pinwheel Galaxy, is a spiral galaxy approximately 40 million light-years away in the constellation Ursa Major. It has two HII regions named NGC 3180 and NGC 3181.
NGC 4725 is an intermediate barred spiral galaxy with a prominent ring structure, located in the northern constellation of Coma Berenices near the north galactic pole. It was discovered by German-born astronomer William Herschel on April 6, 1785. The galaxy lies at a distance of approximately 40 megalight-years from the Milky Way.
NGC 4088 is an intermediate spiral galaxy in the constellation Ursa Major. The galaxy forms a physical pair with NGC 4085, which is located 11′ away.
NGC 2207 and IC 2163 are a pair of colliding spiral galaxies about 80 million light-years away in the constellation Canis Major. Both galaxies were discovered by John Herschel in 1835.
NGC 383 is a double radio galaxy with a quasar-like appearance located in the constellation Pisces. It is listed in Halton C. Arp's 1966 "The Arp Atlas of Peculiar Galaxies." Recent discoveries by the National Radio Astronomy Observatory in 2006 reveal that NGC 383 is being bisected by high energy relativistic jets traveling at relatively high fractions of the speed of light. The relativistic electrons in the jets are detected as synchrotron radiation in the x-ray and radio wavelengths. The focus of this intense energy is the galactic center of NGC 383. The relativistic electron jets detected as synchrotron radiation extend for several thousand parsecs and then appear to dissipate at the ends in the form of streamers or filaments.
NGC 2608 is a barred spiral galaxy located 93 million light-years away in the constellation Cancer. It is 62,000 light-years across, and about 60% of the width of the Milky Way. It is considered a grand design spiral galaxy and is classified as SB(s)b, meaning that the galaxy's arms wind moderately around the prominent central bar.
The NGC 5679 group, also known as Arp 274, is a triplet of galaxies, MCG+1-37-36, MCG+1-37-35 and MCG+1-37-34, spanning about 200000 light-years and at some 400 million light-years from Earth in the constellation Virgo. Arp 247 refers to the Atlas of Peculiar Galaxies, compiled by Halton Arp in 1966. Galaxies 269 through 274 in his catalogue are galaxies that appear to have connected arms.
NGC 5177 is a lenticular galaxy. Based on a redshift of 6467 km/s the galaxy is crudely estimated to be about 300 million light-years away.
SN 2014J was a type-Ia supernova in Messier 82 discovered in mid-January 2014. It was the closest type-Ia supernova discovered for 42 years, and none have been closer as of 2018. The supernova was discovered by chance during an undergraduate teaching session at the University of London Observatory. It peaked on 31 January 2014, reaching an apparent magnitude of 10.5. SN 2014J was the subject of an intense observing campaign by professional astronomers and was bright enough to be seen by amateur astronomers.
NGC 2748 is a spiral galaxy in the northern circumpolar constellation of Camelopardalis, located at a distance of 61.3 megalight-years from the Milky Way. It was discovered September 2, 1828 by John Herschel. The morphological classification of SAbc indicates this is an unbarred spiral with moderate to loosely-wound spiral arms. It is a disk-like peculiar galaxy with a stellar shell that is rotating about the main galactic axis. This shell was most likely formed through the capture and disruption of a dwarf companion. The galactic nucleus likely contains a supermassive black hole with a mass of 4.4+3.5
−3.6×107 M☉, or 44 million times the mass of the Sun.
NGC 3021 is a spiral galaxy in the northern constellation of Leo Minor. It is about 93 million light-years away from Earth, and is receding with a heliocentric radial velocity of 1,537±4 km/s. This galaxy was discovered December 7, 1785 by Anglo-German astronomer William Herschel. The morphological classification of NGC 3021 is SA(rs)bc, which indicates a spiral galaxy with no central bar (SA), an incomplete inner ring structure (rs), and moderate to loosely wound spiral arms (bc).
UGC 8335 is a pair of strongly interacting spiral galaxies. They have been distorted by extreme tidal forces, creating prominent tidal tails and a bridge of gas and stars between the galaxies.
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 7259 is a spiral galaxy approximately 66 million light-years away from Earth in the constellation of Piscis Austrinus. It was discovered by John Herschel on September 28, 1834.
SN 2009ip was a supernova discovered in 2009 in the spiral galaxy NGC 7259 in the constellation of Piscis Austrinus. Since the brightness waned after days post-discovery, it was redesignated as Luminous blue variable (LBV) Supernova impostor.
NGC 2525 is a barred spiral galaxy located in the constellation Puppis. It is located at a distance of about 70 million light years from Earth, which, given its apparent dimensions, means that NGC 2525 is about 60,000 light years across. It was discovered by William Herschel on February 23, 1791.
NGC 918 is a barred spiral galaxy in the constellation Aries about 67 million light years from the Milky Way. It was discovered by John Herschel on Jan 11, 1831.
NGC 782 is a barred spiral galaxy located in the constellation Eridanus about 160 million light-years from the Milky Way. It was discovered by British astronomer John Herschel in 1834.