Messier 93 (NGC 2447) is an open star cluster in constellation Puppis. It was discovered personally by Charles Messier, and cataloged by him in March of 1781.
Messier 93 is about 1° northwest of the 3rd magnitude star 7 Puppis. It is nearly as bright (magnitude 6.0) but less dense than the nearby open cluster M 46. Messier 93 is a rich, luminous, wedge-shaped group; it contains 80 stars of 8th magnitude and fainter in an area 22' in diameter. The stars are grouped in a triangle pointing to the southwest. A few brighter cluster members are scattered east and west and of the wedge.
M 93 lies some 3,600 light years away, and has a true diameter of about 20 light years. Its brightest stars are blue giants of type B9, and its age has been estimated at 100 million years.