IC 5146, the Cocoon Nebula, is a reflection/emission nebula and Caldwell object in the constellation Cygnus. The NGC description refers to IC 5146 as a cluster of 9.5 mag stars involved in a bright and dark nebula. The cluster shines at magnitude +10.0/+9.3/+7.2. It is located near the naked-eye star Pi Cygni.
The cluster is about 4 000 ly away, and the central star that lights it formed about 100,000 years ago. The nebula is about 12 arcmins across, which is equivalent to a span of 15 light years.
IC 5146 is a stellar nursery where star-formation is ongoing. Young stars are seen in both the emission nebula, where gas has been ionized by massive young stars, and in the infrared-dark molecular cloud that forms the “tail”. The most-massive stars in the region is BD +46 3474, a star of class B1 that is an estimated 14±4 times the mass of the sun.
IC 5146, Cocoon Nebula
A very early attempt to photograph the Cocoon Nebula with my CPC 925 reflector telescope and the Nikon D800 DSLR camera in Stuvsta, October 2015.
IC 5146, Cocoon Nebula
Photographed with the APO107 mm refractor telescope and the Atik 360EX monochrome CCD camera in Åva, March 2021. Exposure was a total of 97 min LHaRGB.
IC 5146, Cocoon Nebula
Photographed with the RC8″ reflector telescope and the ASI 2600MC color CMOS camera in Stuvsta, August 30th, 2024. Exposure was 40 *2 min + 5*4 min, i.e. 100 min with L-eXtreme nebula filter. Post-processing in Pixinsight with Blur Xterminator.
IC 5146, Cocoon Nebula
Photographed with the RC8″ reflector telescope and the ASI 2600MC color CMOS camera in Stuvsta, August 30th, 2024. Exposure was 40 *2 min + 5*4 min, i.e. 100 min with L-eXtreme nebula filter. Post-processing in Pixinsight with Blur Xterminator.
