Sharpless 103, Sh2-103 is the gigantic supernova remnant in Cygnus know to most of us as the Veil Nebula or Cygnus Loop. The Supernova remnant that makes up Sharpless 103 exploded between 5000 to 8000 years ago and now covers about 3 degrees and is about 1470 light years away. Possibly 50 light years across. William Herschel is credited with discovering it.
Sh2-103 is made up of lots of the classic SNR features such as rope-like filements
I don't do much wide field astrophotography, so the images of Sharpless Sh2-03 shown here are narrowband closeups on one interesting part. The coloured image is made from mapping Ha to red and OIII to blue and synthesising a green channel.
Other catalog designations
NGC6950 NGC6992 NGC6995 NGC6974 NGC6979