NGC 997 | |
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Observation data (J2000 epoch) | |
Constellation | Cetus |
Right ascension | 02h 37m 14.50s |
Declination | ±07° 18′ 28.0″ |
Redshift | 0.021695 |
Heliocentric radial velocity | 6504 ± 42 km/s |
Distance | 301.6 ± 21.3 Mly (92.48 ± 6.54 Mpc) |
Group or cluster | [CHM2007] HDC 157, [CHM2007] LDC 181, [T2015] nest 200334 |
Characteristics | |
Type | E [1] |
Size | ~105,800 ly (32.44 kpc) (estimated) |
Other designations | |
IRAS F02345+0705, UGC 2102, MCG +01-07-016, CGCG 414-027 | |
NGC 997 is an interacting galaxy in the constellation of Cetus. The galaxy was discovered by Albert Marth on 10 November 1863. [3] It has a regularly rotating central molecular gas disk, containing a black hole of between 4 x 107 and 1.8 x 109 solar masses. [4] Its speed relative to the cosmological background is 6,270 ± 45 km/s, corresponding to a Hubble distance of 92.5 ± 6.5 Mpc (~302 million ly). [2]
NGC 997 is accompanied by PGC 200205, also designated as NGC 997 NED01, [5] a compact galaxy. No data is available for the latter galaxy. So, this pair may be due to an optical alignment, or they may be two gravitationally interacting galaxies about to merge.
One supernova has been observed in NGC 997: SN 2020nej (type Ia, mag. 17). [6]
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 1275 is a type 1.5 Seyfert galaxy located around 237 million light-years away in the direction of the constellation Perseus. NGC 1275 is a member of the large Perseus Cluster of galaxies.
The Atlas of Peculiar Galaxies is a catalog of peculiar galaxies produced by Halton Arp in 1966. A total of 338 galaxies are presented in the atlas, which was originally published in 1966 by the California Institute of Technology. The primary goal of the catalog was to present photographs of examples of the different kinds of peculiar structures found among galaxies.
NGC 3504 is a barred spiral galaxy in the constellation Leo Minor. It has a Hubble distance corresponding to 88 million light-years and was discovered by William Herschel in 1785.
NGC 4697 is an elliptical galaxy some 40 to 50 million light-years away in the constellation Virgo. It is a member of the NGC 4697 Group, a group of galaxies also containing NGC 4731 and several generally much smaller galaxies. This group is about 55 million light-years away; it is one of the many Virgo II Groups, which form a southern extension of the Virgo Supercluster of galaxies.
NGC 4527 is a spiral galaxy in the constellation Virgo. It is a member of the M61 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.
NGC 7007 is a lenticular galaxy with a small bar, around 100 million light-years away from Earth in the constellation Indus. It was discovered by astronomer John Herschel on July 8, 1834. The galaxy is a type 2 seyfert galaxy, and is host to a supermassive black hole with an estimated mass of 4.9 × 107M☉.
NGC 7012 is a large, bright elliptical galaxy located about 380 million light-years away from Earth in the constellation Microscopium. NGC 7012 was discovered by astronomer John Herschel on July 1, 1834. NGC 7012 is also is host to a supermassive black hole with an estimated mass of 4.5 × 109M☉. NGC 7012 is very large galaxy, with an estimated diameter of nearly 300,000 light years.
NGC 7029 is an elliptical galaxy located about 120 million light-years away from Earth in the constellation Indus. NGC 7029 has an estimated diameter of 129,000 light-years. It was discovered by astronomer John Herschel on October 10, 1834. It is in a pair of galaxies with NGC 7022.
NGC 7083 is an unbarred spiral galaxy located about 134 million light-years away in the constellation of Indus. It is also classified as a flocculent spiral galaxy. NGC 7083 was discovered by astronomer James Dunlop on August 28, 1826.
NGC 4473 is an elliptical galaxy located about 50 million light-years away in the constellation of Coma Berenices. It was discovered by astronomer William Herschel on April 8, 1784. NGC 4473 has an inclination of about 71°. NGC 4473 is a member of a chain of galaxies called Markarian's Chain which is part of the larger Virgo Cluster of galaxies.
NGC 7816 is a spiral galaxy located about 215 million light-years away in the constellation of Pisces. It was discovered by astronomer William Herschel on September 26, 1785.
NGC 4454 is a barred spiral galaxy located about 123 million light-years away in the constellation of Virgo. NGC 4454 was discovered by astronomer William Herschel on April 17, 1784.
NGC 4459 is a lenticular galaxy located about 50 million light-years away in the constellation of Coma Berenices. NGC 4459 is also classified as a LINER galaxy. NGC 4459 was discovered by astronomer William Herschel on January 14, 1787. NGC 4459 is a member of the Virgo Cluster.
NGC 4564 is an elliptical galaxy located about 57 million light-years away in the constellation Virgo. NGC 4564 was discovered by astronomer William Herschel on March 15, 1784. The galaxy is also a member of the Virgo Cluster.
NGC 2300 is a lenticular galaxy in the constellation Cepheus. Its velocity with respect to the cosmic microwave background is 1876 ± 7 km/s, which corresponds to a Hubble distance of 90.2 ± 6.3 Mly (27.67 ± 1.94 Mpc). However, 11 non redshift measurements give a distance of 131.98 ± 21.75 Mly (40.464 ± 6.668 Mpc). The galaxy was discovered in 1871 by French astronomer Alphonse Borrelly using an 18 cm telescope.
NGC 4299 is a featureless spiral galaxy located about 55 million light-years away in the constellation Virgo. It was discovered by astronomer William Herschel on March 15, 1784 and is a member of the Virgo Cluster.
NGC 4313 is an edge-on spiral galaxy located about 50 million light-years away in the constellation Virgo. It was discovered by astronomer William Herschel on March 15, 1784. NGC 4313 is a member of the Virgo Cluster and is classified as LINER and as a Seyfert galaxy.
NGC 1320 is a spiral galaxy located in the constellation Eridanus. Its speed relative to the cosmic microwave background is 2,620 ± 15 km/s, which corresponds to a Hubble distance of 38.6 ± 2.7 Mpc. It was discovered by the German-British astronomer William Herschel in 1784.
NGC 3362 is a intermediate spiral galaxy in the constellation of Leo. Its velocity with respect to the cosmic microwave background is 8676 ± 25 km/s, which corresponds to a Hubble distance of 127.97 ± 8.97 Mpc. However, three non redshift measurements give a distance of 95.8 ± 3.984 Mpc. The galaxy was discovered by German astronomer Albert Marth on 22 March 1865.