IC 5146 is a small round emission nebula in northern Cygnus with a prominent large dark nebula, designated Barnard 168, running towards it from the northwest. Several dark lanes are superimposed on the Cocoon Nebula itself. Inside the Cocoon, an open cluster of young stars is developing. Like other such stellar nurseries, the Cocoon Nebula is, at the same time, an emission nebula, a reflection nebula, and an absorption nebula. The nebula's central star, which formed about 100,000 years ago, now provides the energy source for most of the emitted and reflected light of the nebula. The globular structure of the Cocoon Nebula is rare in this part of the Milky Way, which is dominated by large diffuse HII regions. It is located at a distance of about 4,000 light years.

IC 5146 - Cocoon Nebula, Triplet telescope image.