Cygnus Loop - supernova remnant nebula
Cygnus Loop, is a supernova remnant nebula located in the constellation Cygnus .
Cygnus Loop is magnitude and is 3° in size. For reference, the full moon is 30' (arc minutes) or 0.5° in size.
* One can see up to magnitude 7-8 objects with perfect eyes under ideal dark sky conditions.