The Western Veil is part of the Cygnus Loop supernova remnant, the remains of a massive star that exploded between 10,000 and 20,000 years ago around 2,100 light-years away. The bright star that appears to pierce the nebula — 52 Cygni — is actually a foreground star with no physical connection. The delicate filamentary structure results from the shockwave heating gas to millions of degrees as it expands outward at hundreds of kilometres per second.