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, and generally affect both the motions of stars and interstellar gas within spiral galaxies ...

approximately 15 million

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distance, astronomical distances and is equivalent to about 9.46 Orders of magnitude (numbers)#1012, trillion kilometers (), or 5.88 ...

s away in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellation ...

borders of Hydra and

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

Nicolas-Louis de Lacaille Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a French astronomer and geodesist who named 14 out of the 88 constellations. From 1750 to 1754, he studied the sky at the Cape of Good ...

discovered M83 on 23 February 1752 at the

Cape of Good Hope The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is that the Cape of Good Hope is ...

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''. Messier's purpose ...

added it to his catalogue of nebulous objects (now known as the

Messier Catalogue The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his ''Catalogue des Nébuleuses et des Amas d'Étoiles'' (''Catalogue of Nebulae and Star Clusters''). Because Messier was only in ...

) 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 ...

. Its nickname of the Southern Pinwheel derives from its resemblance to the Pinwheel Galaxy (M101).

Characteristics

M83 is a massive,

grand design spiral galaxy A grand design spiral galaxy is a type of spiral galaxy with prominent and well-defined spiral arms, as opposed to multi-arm and flocculent spirals which have subtler structural features. The spiral arms of a grand design galaxy extend clearly a ...

. 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 NGC 5253 is an irregular galaxy in the constellation Centaurus. It was discovered by William Herschel on 15 March 1787. Properties NGC 5253 is located within the M83 Subgroup of the Centaurus A/M83 Group, a relatively nearby galaxy group that i ...

lies near M83, and the two likely interacted within the last billion years resulting in

starburst MicroPro International Corporation was an American software company founded in 1978 in San Rafael, California. They are best known as the publisher of WordStar, a popular early word processor for personal computers. History Founding and early su ...

activity in their central regions. The

star formation Star formation is the process by which dense regions within molecular clouds in The "medium" is present further soon.-->interstellar space

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

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

Galaxy Evolution Explorer Galaxy Evolution Explorer (GALEX or Explorer 83 or SMEX-7) was a NASA orbiting space telescope designed to observe the universe in ultraviolet wavelengths to measure the history of star formation in the universe. In addition to paving the way ...

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

star formation Star formation is the process by which dense regions within molecular clouds in The "medium" is present further soon.-->interstellar space

Supernovae

Six

supernova A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or whe ...

e have been observed in M83: SN 1923A, SN 1945B, SN 1950B, SN 1957D, SN 1968L and SN 1983N.

Environment

M83 is at the center of one of two subgroups within the

Centaurus A/M83 Group The Centaurus A/M83 Group is a complex group of galaxies in the constellations Hydra, Centaurus, and Virgo. The group may be roughly divided into two subgroups. The Cen A Subgroup, at a distance of 11.9 Mly (3.66 Mpc), is centered on Centa ...

, 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 galaxie ...

Centaurus A Centaurus A (also known as NGC 5128 or Caldwell 77) 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 d ...

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 Intermediate spiral galaxies Starburst galaxies Centaurus A/M83 Group Hydra (constellation) 083 NGC objects 48082 17520223 UGCA objects

Characteristics

Supernovae

Environment

See also

References

External links