IC 5146
The Cocoon Nebula

The Cocoon is an emission nebula in Cygnus, surrounding the star cluster IC 5146. It lies about 4,000 light years from Earth and spans a volume of space about 15 light years across.  In the center of the nebula is a bright star that formed about 100,000 years ago. The region of the nebula also contains dusty gas that reflects, rather than emits light and shows up as blue in high resolution photographs. The dusty gas itself obscures much of the light from the nebula which results in a fainter glow than would otherwise be the case. The Cocoon is more easily seen and imaged through a hydrogen alpha filter.

Image taken July 18, with the C-14 operating at F:3.5 and the ST-8 camera binned 2 X 2. Total exposure was 60 minutes, using the RGB process. The red image was taken with a hydrogen alpha filter.