REMASTER EDITION
Messier 83 or
M83, also known as the
Southern Pinwheel Galaxy and
NGC 5236, is a
barred spiral galaxy=10.5px 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.
Charles Messier 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.It has an
isophotal diameter at about 36.24
kiloparsecs (118,000
light-years). Its nickname of the Southern Pinwheel derives from its resemblance to the
Pinwheel Galaxy (M101).CharacteristicsM83 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 rate in M83 is higher along the leading edge of the spiral arms, as predicted by
density wave theory.
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 hitherto been thought that these areas lacked the materials necessary for
star formation.SupernovaeSix
supernovae have been observed in M83: SN 1923A (mag. 14), SN 1945B (mag. 14.2), SN 1950B (mag. 14.5),SN 1957D (mag. 15),SN 1968L (mag. 11.9),and SN 1983N (
type Ia, mag. 11.9).
M83 is at the center of one of two subgroups within the
Centaurus A/M83 Group, a nearby
galaxy group.
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.
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