NGC 2264 – Christmas Tree Cluster

The Christmas Tree Cluster is a young open star cluster in NGC 2264, about 2,500 light-years away in the constellation Monoceros (the Unicorn). Named for its appearance in visible light, it resembles a Christmas tree. This region is of astronomical interest as a very young star-forming area.

The Cone Nebula, a dark nebula associated with an H II region, is embedded in NGC 2264 and forms part of the nebula surrounding the Christmas Tree Cluster. The cone-shaped nebula is formed by a dark absorption nebula of cold molecular hydrogen and dust in front of a faint emission nebula. This emission nebula is ionized by S Monocerotis, the brightest star in NGC 2264. The Cone Nebula extends for about seven light-years in the southern part of NGC 2264.