Rosette Nebula
In
astronomy, the
Rosette Nebula is a large, circular emission
nebula located near one end of a giant molecular cloud in the
Monoceros constellation.
Embedded in the center of the Rosette Nebula is an open cluster. The blue stars in this cluster, labelled NGC 2244, emit ultraviolet light that knocks electrons away from hydrogen atoms. When the electrons fall back, they emit the red light seen here. The Rosette Nebula is about 100 light-years across.
It is believed that stellar winds from a group of O and B stars are exerting pressure on interstellar clouds to cause compression, followed by star formation in the nebula.
The Rosette Nebula has an angular diameter of 1.3° and lies some 900 parsecs or 3000 light years from Earth's Solar System.