DR 21 [SEP] constellation
DR 21
DR 21 is a large molecular cloud located in the constellation Cygnus, discovered in 1966 as a radio continuum source by Downes and Rinehart. DR 21 is located about from Earth and extends for . The region contains a high rate of star formation and is associated with the Cygnus X star forming region. It has an estimated mass of .
A number of different molecules have been detected in the region by their radio emission, including formaldehyde, ammonia, water and carbon monoxide.
In this region, some
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