Messier 50 or M 50, also known as NGC 2323 or the Heart-shaped Cluster, is an open cluster of stars in the constellation Monoceros. It was recorded by G. D. Cassini before 1711 and independently discovered by Charles Messier in 1772 while observing Biela's Comet. It is sometimes described as a 'heart-shaped' figure or a blunt arrowhead.
Open Messier 50 in Monoceros
Sirius and M41 (lower right), M50 (upper left), and NGC 2360 (lower left)
Monoceros is a faint constellation on the celestial equator. Its definition is attributed to the 17th-century cartographer Petrus Plancius. It is bordered by Orion to the west, Gemini to the north, Canis Major to the south, and Hydra to the east. Other bordering constellations include Canis Minor, Lepus, and Puppis.
The constellation Monoceros as it can be seen by the naked eye.
The constellation Monoceros, from Urania's Mirror, a set of star charts from 1825. Includes Canis Minor and the obsolete constellation Printer's Workshop