Messier 83 or M83, also known as the Southern Pinwheel Galaxy and NGC 5236, is a barred spiral galaxy approximately 15 million light-years away in the constellationborders 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. 14.7ly distant.