Messier 83 or M83, also known as the Southern Pinwheel Galaxy and NGC 5236, is a

barred spiral galaxy A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about two thirds of all spiral galaxies in the local universe, and generally affect both the motions of stars and interstellar gas ...

approximately 15 million

light-year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...

s away in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

borders of Hydra and

Centaurus Centaurus () is a bright constellation in the southern sky. One of the 88 modern constellations by area, largest constellations, Centaurus was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one ...

Nicolas-Louis de Lacaille Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a kingdom of France, French astronomer and geodesist who named 14 out of the IAU designated constellations, 88 constellations. From 1750 ...

discovered M83 on 17 February 1752 at the

Cape of Good Hope The Cape of Good Hope ( ) is a rocky headland on the Atlantic Ocean, Atlantic coast of the Cape Peninsula in South Africa. A List of common misconceptions#Geography, common misconception is that the Cape of Good Hope is the southern tip of Afri ...

Charles Messier Charles Messier (; 26 June 1730 – 12 April 1817) was a French astronomer. He published an astronomical catalogue consisting of 110 nebulae and star clusters, which came to be known as the ''Messier objects'', referred to with th ...

added it to his catalogue of nebulous objects (now known as the Messier Catalogue) in March 1781. It is one of the closest and brightest barred spiral galaxies in the sky, and is visible with

binoculars Binoculars or field glasses are two refracting telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. Most binoculars are sized to be held ...

. It has an isophotal diameter at about . Its nickname of the Southern Pinwheel derives from its resemblance to the

Pinwheel Galaxy The Pinwheel Galaxy (also known as Messier 101, M101 or NGC 5457) is a face-on, counterclockwise intermediate spiral galaxy located from Earth in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 and was communicated ...

(M101).

Characteristics

M83 is a massive, grand design spiral galaxy. Its morphological classification in the De Vaucouleurs system is SAB(s)c, 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. The peculiar dwarf galaxy NGC 5253 lies near M83, and the two likely interacted within the last billion years resulting in starburst activity in their central regions. The

star formation Star formation is the process by which dense regions within molecular clouds in interstellar space—sometimes referred to as "stellar nurseries" or "star-forming regions"—Jeans instability, collapse and form stars. As a branch of astronomy, sta ...

rate in M83 is higher along the leading edge of the spiral arms, as predicted by

density wave theory Density wave theory or the Lin–Shu density wave theory is a theory proposed by C.C. Lin and Frank Shu in the mid-1960s to explain the spiral arm structure of spiral galaxies. The Lin–Shu theory introduces the idea of long-lived quasistati ...

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

's Galaxy Evolution Explorer project on 16 April 2008 reported finding large numbers of new stars in the outer reaches of the galaxy— from the center. It had been thought that these areas lacked the materials necessary for

. In April 2025 it was published that first clues were found for the possible existence of a

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun (). Black holes are a class of astronomical ...

at the center of M83.

Supernovae

Six

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

e have been observed in M83: * SN 1923A (type unknown, mag. 14) was discovered by

Carl Otto Lampland Carl Otto Lampland (December 29, 1873 – December 14, 1951) was an American astronomer. He was involved with both of the Lowell Observatory solar system projects, observations of the planet Mars and the search for Planet X. Biography Ca ...

on 5 May 1923. * SN 1945B (type unknown, mag. 14.2) was discovered by William Liller on 13 July 1945. * SN 1950B (type unknown, mag. 14.5) was discovered by Guillermo Haro on 15 March 1950. * SN 1957D (type unknown, mag. 15) was discovered by H. S. Gates on 28 December 1957. * SN 1968L ( type II-P, mag. 11.9) was discovered by J. C. Bennett on 17 July 1968. * SN 1983N ( type Ia, mag. 11.9) was discovered by

Robert Evans Robert Evans (born Robert J. Shapera; June 29, 1930 – October 26, 2019) was an American film producer who worked on ''Rosemary's Baby (film), Rosemary's Baby'' (1968), ''Love Story (1970 film), Love Story'' (1970), ''The Godfather'' (1972), ...

from Australia on 3 July 1983. On 6 July, it was observed with the

Very Large Array The Karl G. Jansky Very Large Array (VLA) is a centimeter-wavelength radio astronomy observatory in the southwestern United States built in the 1970s. It lies in central New Mexico on the Plains of San Agustin, between the towns of Magdalena, Ne ...

and became the first type I supernova to have a radio emission detected. The supernova reached peak optical brightness on 17 July, achieving an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...

of 11.54. Although identified as type I, the spectrum was considered peculiar. A year after the explosion, about 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. SN 1983N became the modern prototype of a hydrogen deficient type Ib supernova, with the progenitor being inferred as a

Wolf–Rayet star Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectroscopy, spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or carbon. The spectra indicate very ...

Environment

M83 is at the center of one of two subgroups within the Centaurus A/M83 Group, a nearby

galaxy group A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxi ...

. Centaurus A is at the center of the other subgroup. These are sometimes identified as one group, and sometimes as two. 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.

References

External links

*
ESO Photo Release eso0136, An Infrared Portrait of the Barred Spiral Galaxy Messier 83

* ttps://web.archive.org/web/20130112044352/http://www.dsi-astronomie.de/M83.html M83 The Southern Pinwheel
X-rays Discovered From Young Supernova Remnant
(SN 1957D) *
Messier 83 (Southern Pinwheel Galaxy) at Constellation Guide
{{DEFAULTSORT:Messier 083 17520223 Barred spiral galaxies Centaurus A/M83 Group Hydra (constellation) Intermediate spiral galaxies 083 -05-32-050 NGC objects 048082 444-081 13341-2936 Starburst galaxies 366

Characteristics

Supernovae

Environment

See also

References

External links