NGC 644 | |
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![]() DECam image of NGC 644 | |
Observation data (J2000 epoch) | |
Constellation | Phoenix |
Right ascension | 01h 38m 52.975s [1] |
Declination | −42° 35′ 07.19″ [1] |
Redshift | 0.020731 [2] |
Heliocentric radial velocity | 6151 km/s [2] |
Distance | 268.8 Mly (82.41 Mpc) [3] |
Apparent magnitude (B) | 14.79 [2] |
Characteristics | |
Type | SB(r)bc: [4] |
Size | 126.8 kly (38.88 kpc) [4] |
Other designations | |
MCG -07-04-027, PGC 6097 [2] |
NGC 644 is a barred spiral galaxy in the constellation Phoenix in the southern sky. It is estimated to be 270 million light-years from the Milky Way and has a diameter of approximately 130,000 light-years. [4] Together with NGC 641, it probably forms a gravitationally bound pair of galaxies. The object was discovered on September 5, 1834 by John Herschel. [5] [6]
Two supernovae have been observed in NGC 644: SN 2011gm (type Ia, mag. 15.8), [7] and SN 2018cmj (type II, mag. 17.1). [8]
Messier 66 or M66, also known as NGC 3627, is an intermediate spiral galaxy in the southern, equatorial half of Leo. It was discovered by French astronomer Charles Messier on 1 March 1780, who described it as "very long and very faint". This galaxy is a member of a small group of galaxies that includes M65 and NGC 3628, known as the Leo Triplet or the M66 Group. M65 and M66 are a common object for amateur astronomic observation, being separated by only 20′.
Messier 99 or M99, also known as NGC 4254 or St. Catherine's Wheel, is a grand design spiral galaxy in the northern constellation Coma Berenices approximately 15,000,000 parsecs from the Milky Way. It was discovered by Pierre Méchain on 17 March 1781. The discovery was then reported to Charles Messier, who included the object in the Messier Catalogue of comet-like objects. It was one of the first galaxies in which a spiral pattern was seen. This pattern was first identified by Lord Rosse in the spring of 1846.
NGC 4051 is an intermediate spiral galaxy in the constellation of Ursa Major. It was discovered on 6 February 1788 by John Herschel.
NGC 935 and IC 1801 are a pair of interacting galaxies within the Aries constellation. They were discovered on 18 September 1885 by Lewis Swift. NGC 935 is the northern member of the pair, and IC 1801 is the southern. Together, they are listed in Halton Arp's Atlas of Peculiar Galaxies as Arp 276, as an example of interacting galaxies.
NGC 5490 is a large elliptical galaxy located in the constellation of Boötes. Its velocity relative to the cosmic microwave background is 5,075 ± 22 km/s, which corresponds to a Hubble distance of 244.1 ± 17.1 Mly (74.85 ± 5.25 Mpc). In addition, 13 non-redshift measurements gives a distance of 269.98 ± 15.01 Mly (82.777 ± 4.603 Mpc). NGC 5490 was discovered by the German-British astronomer William Herschel on 14 March 1784.
NGC 5754 is a barred spiral galaxy located 218 million light years away in the constellation Boötes. It was discovered by German-British astronomer William Herschel on 16 May 1787.
NGC 23 is a spiral galaxy located in the northern constellation of Pegasus, around 173.5 megalight-years distant from the Milky Way. It was discovered by William Herschel on 10 September 1784. In the Webb Society Deep-Sky Observer's Handbook, the visual appearance of NGC 23 is described as follows:
Bright, extended ellipse; a bright nuclear structure is noticeably elongated; two weak spiral enhancements emerge from opposite sides of the nucleus, one curving towards a bright star attached on the south end. The galaxy is likely interacting with NGC 9.
NGC 4217 is an edge-on spiral galaxy which lies approximately 60 million light-years away in the constellation of Canes Venatici. It is a possible companion galaxy to Messier 106.
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 109 is a spiral galaxy estimated to be about 240 million light-years away in the constellation of Andromeda. It was discovered by Heinrich d'Arrest in 1861 and its magnitude is 13.7.
NGC 2613 is a spiral galaxy in the southern constellation of Pyxis, next to the western constellation border with Puppis. It was discovered by the German-born astronomer William Herschel on November 20, 1784. With an apparent visual magnitude of 10.5, the galaxy is faintly visible using a telescope with a 100 mm (4 in) aperture. It appears spindle-shaped as it is almost edge-on to observers on Earth.
NGC 1084 is an unbarred spiral galaxy in the constellation Eridanus. It is located at a distance of about 63 million light-years away from the Milky Way. The galaxy was discovered by William Herschel on 10 January 1785. It has multiple spiral arms, which are not well defined. It belongs in the same galaxy group with NGC 988, NGC 991, NGC 1022, NGC 1035, NGC 1042, NGC 1047, NGC 1052 and NGC 1110. This group is in turn associated with the Messier 77 group.
NGC 560 is a lenticular galaxy in the constellation Cetus. It is estimated to be about 250 million light-years from the Milky Way and has a diameter of approximately 150,000 light years. It is part of the Abell 194 galaxy cluster. NGC 560 was discovered on October 1, 1785 by the German-British astronomer William Herschel.
NGC 2227 is a barred spiral galaxy with a morphological type of SB(rs)c located in the direction of the Canis Major constellation. It was discovered on January 27, 1835, by John Herschel.
NGC 550 is a spiral galaxy in the constellation Cetus. It is estimated to be about 300 million light-years from the Milky Way and has a diameter of approximately 110,000 light years. The German-British astronomer William Herschel discovered it on 8 October 1785.
NGC 812 is a spiral galaxy located in the Andromeda constellation, an estimated 175 million light-years from the Milky Way. NGC 812 was discovered on December 11, 1876 by astronomer Édouard Stephan.
NGC 813 is a lenticular galaxy in the constellation Hydrus. It is estimated to be 390 million light-years from the Milky Way and has a diameter of approximately 140,000 ly. NGC 813 was discovered on November 24, 1834, by the British astronomer John Herschel.
NGC 996 is an elliptical galaxy of the Hubble type E0 in the constellation Andromeda. It is estimated to be 210 million light years from the Milky Way and has a diameter of approximately 75,000 ly. It was discovered on December 7, 1871 by astronomer Édouard Stephan.
NGC 941 is an intermediate spiral galaxy in the constellation Cetus. It is an estimated 16.83 MPc from the Milky Way and has a diameter of approximately 55,000 light years. The galaxies NGC 926, NGC 934, NGC 936, NGC 955 are located in the same sky area. NGC 941 was discovered by the astronomer William Herschel on 6 January 1785.
NGC 706 is a spiral galaxy located in the Pisces constellation about 230 million light years from the Milky Way. It was discovered by the German–British astronomer William Herschel in 1786.