Also known as the "Skull Nebula" and Caldwell 49, the Rosette Nebula is a large HII region of bright gas and filaments of dark dust, located in the constellation of Monoceros. The open cluster NGC 2244 (discovered by John Flamsteed in 1690) is associated with this region - the stars of which were formed within this molecular cloud. Located 5000 light years away, and measuring 65 light years in diameter,