A large supernova remnant in the constellation Cygnus, measuring nearly 3° across. Some arcs of the Loop, known collectively as the Veil Nebula (or sometimes the Cirrus Nebula), are visible at optical wavelengths; radio, infrared and x-ray images reveal the complete Loop. The brightest part of the Veil is NGC 6992–5, to the east (centered on position RA 20 h 56.4 m, dec