Messier 83

Lore & Background

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 in March 1781. Its morphological classification in the De Vaucouleurs system is SAB(s)c, indicating a weak-barred spiral with loosely wound arms and no ring structure. 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. On 16 April 2008, NASA's Galaxy Evolution Explorer project reported finding large numbers of new stars in the outer reaches of the galaxy—20 kpc from the center—areas previously thought to lack materials necessary for star formation. In April 2025, it was published that first clues were found for the possible existence of a supermassive black hole at the center of M83.

Six supernovae have been observed in M83, including SN 1983N, which became the modern prototype of a hydrogen-deficient Type Ib supernova, with the progenitor inferred as a Wolf–Rayet star. M83 is at the center of one of two subgroups within the Centaurus A/M83 Group, a nearby galaxy group; the two subgroups appear not to be moving relative to each other.

Reader's Guide

Messier 83 is notable as one of the closest and brightest barred spiral galaxies, making it a frequent target for amateur and professional astronomers. Its discovery by Nicolas-Louis de Lacaille in 1752 at the Cape of Good Hope and its inclusion by Charles Messier in 1781 highlight its historical significance. The galaxy's grand design spiral structure and high star formation rate, especially along the leading edges of its arms, provide a natural laboratory for testing density wave theory. The 2008 discovery of new stars in its outer reaches challenged previous assumptions about star formation environments. The possible detection of a supermassive black hole at its center, announced in April 2025, adds to its astrophysical importance. The six supernovae observed in M83, particularly SN 1983N, have contributed to the understanding of supernova types and progenitor systems, including the first unambiguous detection of a large amount of iron in supernova ejecta. As the center of one subgroup within the Centaurus A/M83 Group, M83 plays a key role in studies of galaxy interactions and group dynamics.

Did You Know?

• M83 was discovered by Nicolas-Louis de Lacaille on 17 February 1752 at the Cape of Good Hope.
• SN 1983N in M83 was the first Type I supernova to have a radio emission detected.
• The galaxy's nickname 'Southern Pinwheel' derives from its resemblance to the Pinwheel Galaxy (M101).

A Number in a Legendary List

M83 occupies a place in one of the most celebrated compilations in all of astronomy. The Messier catalogue, originally assembled by Charles Messier and his assistant Pierre Méchain, began as a practical tool: a running list of bright, non-comet objects that kept derailing Messier's obsessive search for new comets. What started as 45 unnumbered entries in a 1774 memo submitted to the French Academy of Sciences grew steadily, reaching 70 objects by 1780 and a final 103 in the 1781 edition published in the Connaissance des Temps. Later astronomers, poring over marginalia and side notes in Messier's and Méchain's manuscripts, pushed the count to 110. M83 stands among this diverse roster of galaxies, nebulae, and star clusters, and to this day it is referenced far more often by its simple Messier designation than by any other catalog number.

One of the Spectacular Few

The Messier objects are not random picks plucked from the night sky. They represent, in nearly every category of deep-sky phenomenon—diffuse nebulae, planetary nebulae, open clusters, globular clusters, and galaxies—some of the most visually striking examples visible from European latitudes. Crucially, nearly every entry sits near the top of the closeness rankings within its category, meaning they are among the nearest members of their class to Earth. This proximity means modern professional instruments can resolve fine structural details in them, and that even a modest 100-millimeter refractor, the kind Messier himself used from his Paris base, could render them visible through glass. M83, as a galaxy within this elite group, benefits from that same combination of brightness and closeness that made it a natural inclusion in a list designed to capture the sky's most impressive sights.

Compiled from the Rooftops of Paris

The entire Messier catalogue, of which M83 is a member, was born from a single vantage point: the Hôtel de Cluny in Paris, now home to the Musée national du Moyen Âge. Messier and Méchain worked from this location, and their observational window was constrained by geography. Their list encompasses objects spanning from the north celestial pole down to roughly −35.7° in celestial latitude, meaning they deliberately excluded targets visible only from much more southerly latitudes, such as the Magellanic Clouds. This geographic limitation shaped the catalogue's character, filling it with objects that a mid-northern observer could realistically track across the seasons. The final edition was published in the Connaissance des Temps pour l'Année 1784, France's official yearly ephemeris, cementing its status as a reference work for the broader astronomical community.

A Marathon for the Modern Eye

More than two centuries after Messier first jotted down his frustrating non-comet targets, the catalogue remains a living resource. Amateur astronomers worldwide still reach for Messier numbers as shorthand for some of the most rewarding visual and photographic targets available. In early spring, dedicated observers gather for so-called Messier marathons, attempting to sweep through all 110 entries in a single night as the sky rotates through the appropriate constellations. Modern equipment with apertures far exceeding Messier's modest refractor makes these objects even more accessible, revealing structural details that would have been invisible in the eighteenth century. M83, like its catalogued neighbors, continues to draw both casual backyard stargazers and serious astrophotographers, ensuring that a list born out of comet-hunting frustration endures as a gateway to the deep sky.

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