Arp 166 | |
---|---|
Observation data (J2000.0 epoch) | |
Constellation | Triangulum |
Right ascension | 01h 57m 32.00s [1] |
Declination | +33° 12′ 24.00″ [1] |
Redshift | 0.017529 [2] |
Helio radial velocity | 5255 km/s [2] |
Distance | 225 Mly [3] |
Apparent magnitude (B) | 12.90 [1] |
Characteristics | |
Type | Pair of galaxies E0+E [2] |
Apparent size (V) | 2.5 x 1.7 [2] |
Other designations | |
NGC 750, NGC 751 |
Arp 166 is a pair of interacting elliptical galaxies approximately 225 million light-years away from Earth in the constellation of Triangulum. [2] [3] The two galaxies, NGC 750 and NGC 751, are listed together as Arp 166 in the Atlas of Peculiar Galaxies (in the category Galaxies with diffuse filaments). [4]
Arp 166 was discovered by German-born British astronomer William Herschel on September 12, 1784, but he did not resolve this close pair of galaxies, therefore he described it as a single object NGC 750. [4] [3]
Arp 166 was first seen as a double by Irish engineer and astronomer Bindon Stoney on October 11, 1850, who used Lord Rosse's 72" telescope. [4] The second galaxy from this pair, which is smaller and fainter than NGC 750, was catalogued as NGC 751. [4]
At least 100,000,000 years have passed since the moment of the first strong tidal perturbation between these two galaxies. [5] Both galaxies are characterized by strong tidal interactions and distortions, and they are still in the process of efficient tidal interaction. [5]
The distance between the centers of this pair is 21", or 10 kpc in projection. [6] [5] Both galaxies have almost identical central radial velocities. [5] While NGC 750 exhibits nearly flat radial velocity curves, the radial velocity curves of NGC 751 are characterized by large variations of more than 100 km s−1 along the slit. [5]
A large, diffuse tidal tail extends 20 arcsec (10 kpc) to the north-east of the pair. [5]
Messier 49 is a giant elliptical galaxy about 56 million light-years away in the equatorial constellation of Virgo. This galaxy was discovered by astronomer Charles Messier in 1777.
Messier 60 or M60, also known as NGC 4649, is an elliptical galaxy approximately 57 million light-years away in the equatorial constellation of Virgo. Together with NGC 4647, it forms a pair known as Arp 116. Messier 60 and nearby elliptical galaxy Messier 59 were discovered by Johann Gottfried Koehler in April 1779, observing a comet in the same part of the sky. Charles Messier added both to his catalogue about three days after this.
NGC 5195 is a dwarf galaxy that is interacting with the Whirlpool Galaxy. Both galaxies are located approximately 25 million light-years away in the constellation Canes Venatici. Together, the two galaxies are one of the most famous interacting galaxy pairs.
NGC 1512 is a barred spiral galaxy approximately 38 million light-years away from Earth in the constellation Horologium. The galaxy displays a double ring structure, with a (nuclear) ring around the galactic nucleus and an (inner) further out in the main disk. The galaxy hosts an extended UV disc with at least 200 clusters with recent star formation activity. NGC 1512 is a member of the Dorado Group.
NGC 520 is a pair of colliding spiral galaxies about 105 million light-years away in the constellation Pisces. They were discovered by astronomer William Herschel on 13 December 1784.
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 5090 and NGC 5091 are a set of galaxies approximately 160 million light-years away in the constellation Centaurus. They are in the process of colliding and merging with some evidence of tidal disruption of NGC 5091.
NGC 278 is an isolated spiral galaxy in the northern circumpolar constellation of Cassiopeia, near the southern constellation boundary with Andromeda. It lies at a distance of approximately 39 megalight-years from the Milky Way, giving it a physical scale of 190 ly (58 pc) per arcsecond. The galaxy was discovered on December 11, 1786 by German-born astronomer William Herschel. J. L. E. Dreyer described it as, "considerably bright, pretty large, round, 2 stars of 10th magnitude near".
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 6286 is an interacting spiral galaxy located in the constellation Draco. It is designated as Sb/P in the galaxy morphological classification scheme and was discovered by the American astronomer Lewis A. Swift on 13 August 1885. NGC 6286 is located at about 252 million light years away from Earth. NGC 6286 and NGC 6285 form a pair of interacting galaxies, with tidal distortions, categorized as Arp 293 in the Arp Atlas of Peculiar Galaxies.
NGC 4647 is an intermediate spiral galaxy estimated to be around 63 million light-years away in the constellation of Virgo. It was discovered by astronomer William Herschel on March 15, 1784. NGC 4647 is listed along with Messier 60 as being part of a pair of galaxies called Arp 116; their designation in Halton Arp's Atlas of Peculiar Galaxies. The galaxy is located on the outskirts of the Virgo Cluster.
NGC 508, also occasionally referred to as PGC 5099 or UGC 939, is an elliptical galaxy in the constellation Pisces. It is located approximately 247 million light-years from the Solar System and was discovered on 12 September 1784 by British astronomer William Herschel.
NGC 2936 is an interacting spiral galaxy located at a distance of 326 million light years, in the constellation Hydra. NGC 2936 is interacting with elliptical galaxy NGC 2937, located just beneath it. They were both discovered by Albert Marth on Mar 3, 1864. To some astronomers, the galaxy looks like a penguin or a porpoise. NGC 2936, NGC 2937, and PGC 1237172 are included in the Atlas of Peculiar Galaxies as Arp 142 in the category "Galaxy triplet".
NGC 612 is a lenticular galaxy in the constellation of Sculptor located approximately 388 million light-years from Earth. It is a type II Seyfert galaxy and thus has an active galactic nucleus. NGC 612 has been identified as an extremely rare example of a non-elliptical radio galaxy, hosting one of the nearest powerful FR-II radio sources.
NGC 680 is an elliptical galaxy located in the constellation Aries. It is located at a distance of circa 120 million light years from Earth, which, given its apparent dimensions, means that NGC 680 is about 100,000 light years across. It was discovered by William Herschel on September 15, 1784.
NGC 4294 is a barred spiral galaxy with flocculent spiral arms located about 55 million light-years away in the constellation Virgo. The galaxy was discovered by astronomer William Herschel on March 15, 1784 and is a member of the Virgo Cluster.
NGC 739 is a spiral galaxy approximately 193 million light-years away from Earth in the constellation of Triangulum.
NGC 750 is an elliptical galaxy approximately 225 million light-years away from Earth in the constellation of Triangulum. It forms a close pair of interacting galaxies together with the nearby NGC 751 galaxy. The pair is listed as Arp 166 in the Atlas of Peculiar Galaxies.
NGC 751 is an elliptical galaxy approximately 225 million light-years away from Earth in the constellation of Triangulum. It forms a close pair of interacting galaxies together with the nearby NGC 750 galaxy. The pair is listed as Arp 166 in the Atlas of Peculiar Galaxies.
NGC 4305 is a dwarf spiral galaxy located about 100 million light-years away in the constellation Virgo. The galaxy was discovered by astronomer John Herschel on May 2, 1829. Although considered to be a member of the Virgo Cluster, its high radial velocity and blue luminosity suggest it is in fact a background galaxy. The galaxy has a nearby major companion; NGC 4306.