Explore the Cocoon Nebula: A Stellar Nursery in Cygnus

 The Cocoon Nebula, alternatively referred to as IC 5146, Barnard 168, and Sh2-125, is a unique celestial spectacle of both emission and reflection nebula. Positioned in the far-off constellation of Cygnus, this nebula sits approximately 2,500 light-years away from us. Based on its distance, it is estimated by astronomers that the Cocoon spans about 15 light-years in diameter. Its discovery dates back to July 28th, 1894, credited to Max Wolf.

This magnificent Cocoon Nebula is a hotbed of active star formation. Through the use of X-ray and infrared observational tools, astronomers have pinpointed hundreds of what are known as young stellar objects within its confines. These objects can be found populating both the emission nebula and the dark molecular cloud, the latter forming a tail-like structure. 

The Cocoon Nebula is home to one of the most massive stars in the region, BD+46 3474. This B1-type star boasts a mass equivalent to 14 times that of our Sun. Another noteworthy star is BD+46 3471, a star of intermediate mass known as a Herbig Ae/Be star, characterized by 2-8 solar masses and a spectrum showcasing intense emission lines.

Image: This is a composite optical image of the Cocoon Nebula, captured using a compact amateur telescope. The image was generated by combining the results of broadband filters (RGB) with a narrow-band filter focused on the emission of ionised hydrogen (Hα, in red).

Image Credit: Kevin Morefield & Curtistsai, courtesy of @astrobin.