* Astronomy

Barnard 168 is a dark molecular cloud located about 500-light-years away in the constellation Cygnus. The lighter haze is the Cocoon Nebula is directly connected to the dark cloud. The dark cloud has a mass of about 2,500 solar masses.

The catalogue name of the dark cloud comes from the astronomer Edward Emerson Barnard who compiled a catalogue of dark nebulae in 1919. 

When viewing IC 5146, dark nebula Barnard 168 (B168) is an inseparable part of the experience, forming a dark lane that surrounds the cluster and projects westward forming the appearance of a trail behind the Cocoon.
Source

Right Ascension21h 53m 20s, Declension+47° 16"