The Cocoon Nebula, cataloged as IC 5146, is a strikingly beautiful emission nebula and star cluster located about 4,000 light years away in the constellation Cygnus. It is located near the star Pi Cygni, the open cluster NGC 7209 in Lacerta, and the bright open cluster M 39.
IC 5146 shines at magnitude 7.2, and has an apparent diameter of 12', which is equivalent to a span of 15 light years.
Like other stellar nurseries, the Cocoon Nebula holds a bright red emission nebula, blue reflection nebulae, and dark absorption nebulae. Inside the Cocoon Nebula is a newly developing cluster of stars. The massive central star, which formed about 100,000 years ago, now provides the energy source for much of the emitted and reflected light from this nebula.
When viewing IC 5146, dark nebula Barnard 168 is an inseparable part of the experience. It forms a dark lane that surrounds the cluster and projects westward, forming the appearance of a trail behind the Cocoon.