Messier 83 | |
---|---|
Observation data (J2000 epoch) | |
Constellation | Hydra |
Right ascension | 13h 37m 00.919s [1] |
Declination | −29° 51′ 56.74″ [1] |
Redshift | 0.001721±0.000013 [2] |
Heliocentric radial velocity | 508 km/s [3] |
Distance | 14.7 Mly (4.50 Mpc) [3] |
Apparent magnitude (V) | 7.6 [4] |
Characteristics | |
Type | SAB(s)c [2] |
Size | 36.24 kiloparsecs (118,000 light-years) (diameter; 26.0 mag/arcsec2 B-band isophote) [2] |
Apparent size (V) | 12′.9 × 11′.5 [5] |
Other designations | |
Southern Pinwheel Galaxy, NGC 5236, PGC 48082, UGCA 366 [6] |
Messier 83 or M83, also known as the Southern Pinwheel Galaxy and NGC 5236, is a barred spiral galaxy [7] approximately 15 million light-years away in the constellation borders of Hydra and Centaurus. Nicolas-Louis de Lacaille discovered M83 on 17 February 1752 at the Cape of Good Hope. [8] Charles Messier added it to his catalogue of nebulous objects (now known as the Messier Catalogue) in March 1781. [8]
It is one of the closest and brightest barred spiral galaxies in the sky, and is visible with binoculars. [9] It has an isophotal diameter at about 36.24 kiloparsecs (118,000 light-years ). Its nickname of the Southern [lower-alpha 1] Pinwheel derives from its resemblance to the Pinwheel Galaxy (M101).
M83 is a massive, grand design spiral galaxy. [10] Its morphological classification in the De Vaucouleurs system is SAB(s)c, [2] where the 'SAB' denotes a weak-barred spiral, '(s)' indicates a pure spiral structure with no ring, and 'c' means the spiral arms are loosely wound. [11] The peculiar dwarf galaxy NGC 5253 lies near M83, [12] and the two likely interacted within the last billion years resulting in starburst activity in their central regions. [10]
The star formation rate in M83 is higher along the leading edge of the spiral arms, as predicted by density wave theory. [13] NASA's Galaxy Evolution Explorer project on 16 April 2008 reported finding large numbers of new stars in the outer reaches of the galaxy—20 kpc from the center. It had been thought that these areas lacked the materials necessary for star formation. [14] [15]
Six supernovae have been observed in M83: SN 1923A (mag. 14), [16] SN 1945B (mag. 14.2), [17] SN 1950B (mag. 14.5), [18] SN 1957D (mag. 15), [19] [20] SN 1968L (type II-P, mag. 11.9), [21] [22] and SN 1983N (type Ia, mag. 11.9). [23]
SN 1983N was discovered by Robert Evans from Australia on July 3, 1983. [24] On July 6, it was observed with the Very Large Array and became the first type I supernova to have a radio emission detected. The supernova reached peak optical brightness on July 17, achieving an apparent visual magnitude of 11.54. [25] Although identified as type I, the spectrum was considered peculiar. A year after the explosion, about 0.3 M☉ of iron was discovered in the ejecta. This was the first time that such a large amount of iron was unambiguously detected from a supernova explosion. [26] SN 1983N became the modern prototype of a hydrogen deficient type Ib supernova, with the progenitor being inferred as a Wolf–Rayet star. [27]
M83 is at the center of one of two subgroups within the Centaurus A/M83 Group, a nearby galaxy group. [28] Centaurus A is at the center of the other subgroup. These are sometimes identified as one group, [29] [30] and sometimes as two. [31] However, the galaxies around Centaurus A and the galaxies around M83 are physically close to each other, and both subgroups appear not to be moving relative to each other. [32]
The Pinwheel Galaxy is a face-on, unbarred, and counterclockwise spiral galaxy located 21 million light-years from Earth in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 and was communicated that year to Charles Messier, who verified its position for inclusion in the Messier Catalogue as one of its final entries.
Messier 61 is an intermediate barred spiral galaxy in the Virgo Cluster of galaxies. It was first discovered by Barnaba Oriani on May 5, 1779, six days before Charles Messier discovered the same galaxy. Messier had observed it on the same night as Oriani but had mistaken it for a comet. Its distance has been estimated to be 45.61 million light years from the Milky Way Galaxy. 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.
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. It is the closest radio galaxy to Earth, as well as the closest BL Lac object, 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.
The Whirlpool Galaxy, also known as Messier 51a (M51a) or NGC 5194, is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus. It lies in the constellation Canes Venatici, and was the first galaxy to be classified as a spiral galaxy. It is 7.22 megaparsecs away and 23.58 kiloparsecs (76,900 ly) in diameter.
Messier 81 (also known as NGC 3031 or Bode's Galaxy) is a grand design spiral galaxy about 12 million light-years away in the constellation Ursa Major. It has a D25 isophotal diameter of 29.44 kiloparsecs (96,000 light-years). Because of its relative proximity to the Milky Way galaxy, large size, and active galactic nucleus (which harbors a 70 million M☉ supermassive black hole), Messier 81 has been studied extensively by professional astronomers. The galaxy's large size and relatively high brightness also makes it a popular target for amateur astronomers. In late February 2022, astronomers reported that M81 may be the source of FRB 20200120E, a repeating fast radio burst.
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.
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 3184, the Little Pinwheel Galaxy, is a spiral galaxy approximately 40 million light-years away in the constellation Ursa Major. Its name comes from its resemblance to the Pinwheel Galaxy. It was discovered on 18 March 1787 by German-British astronomer William Herschel. It has two HII regions named NGC 3180 and NGC 3181.
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 7331, also known as Caldwell 30, is an unbarred spiral galaxy about 40 million light-years (12 Mpc) away in the constellation Pegasus. It was discovered by William Herschel in 1784. NGC 7331 is the brightest galaxy in the field of a visual grouping known as the NGC 7331 Group of galaxies. In fact, the other members of the group, NGC 7335, 7336, 7337 and 7340, lie far in the background at distances of approximately 300–350 million light years.
NGC 4945 (also known as Caldwell 83) is a barred spiral galaxy in the constellation Centaurus, visible near the star Xi Centauri. The galaxy was discovered by James Dunlop in 1826 and is thought to be similar to the Milky Way Galaxy, although X-ray observations show that NGC 4945 has an unusual energetic Seyfert 2 nucleus that might house a supermassive black hole. Around the nucleus of the galaxy, there is a dense disk of dust and gas, along with many dense star clusters. This object has an estimated mass of 1.4+1.4
−0.7×1011 M☉.
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 5253 is an irregular galaxy in the constellation Centaurus. It was discovered by William Herschel on 15 March 1787.
NGC 4622 is a face-on unbarred spiral galaxy with a very prominent ring structure located in the constellation Centaurus. The galaxy is a member of the Centaurus Cluster.
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 922 is a peculiar galaxy in the southern constellation of Fornax, located at a distance of 142 Mly from the Milky Way. It is one of the nearest known collisional galaxies. This object was described by the Herschels as "considerably faint, pretty large, round, gradually pretty much brighter middle." The general form is described by the morphological classification of SB(s)cd pec, which indicates a peculiar (pec) barred spiral galaxy (SB) with no inner ring system around the bar (s) and loosely-wound spiral arms (cd).
NGC 5668 is a nearly face-on spiral galaxy, visual magnitude about 11.5, located about 81 million light years away in the constellation Virgo. It was discovered on 29 April 1786 by William Herschel. It is a member of the NGC 5638 Group of galaxies, itself one of the Virgo III Groups strung out to the east of the Virgo Supercluster of galaxies. In addition, A.M. Garcia listed NGC 5668 in the 31 member NGC 5746 galaxy group.
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 4939 is a spiral galaxy located in the constellation Virgo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 4939 is about 190,000 light years across. It was discovered by William Herschel on March 25, 1786.
{{cite book}}
: CS1 maint: multiple names: authors list (link)