Object Analysis

The Rosette Nebula (Caldwell 49) is a large, spherical H II region located near one end of a giant molecular cloud in the Monoceros region of the Milky Way Galaxy. The open cluster NGC 2244 (Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula's matter.

The cluster and nebula lie at a distance of some 5,000 light-years from Earth and measure roughly 130 light-years in diameter. The radiation from the young stars excites the atoms in the nebula, causing them to emit radiation themselves producing the emission nebula we see. The mass of the nebula is estimated to be around 10,000 solar masses.

Visually, the nebula appears like a ghostly wreath around the star cluster. Photographically, it is a stunning floral arrangement of red hydrogen gas and dark dust filaments, earning it the name "Rosette."