The Rosette Nebula is a large, circular 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 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 5,200 light years from Earth (although estimates of the distance vary considerably) and measure roughly 130 light years in diameter. The radiation from the young stars excite 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.
Exposure: 30 x 5 minutes
Camera: Modified Canon Digital Rebel XT (350D)
Scope: Astro-Tech AT80ED 80mm APO refractor, TeleVue 1.1x field flattener
Mount: Meade LX200
Guider: Meade LX200 @ f/3.3
Filter: Astronomik CLS
Software: PHD Guiding, Nebulosity, Photoshop