Veil Nebula

The Veil is the visible remnant of a supernova explosion, the collapse of a massive star roughly 8 times the Sun's mass, that occurred between 10,000 and 20,000 years ago. The expanding shock wave still races outward at over 100 miles per second. It was not recorded by any known contemporary observers.

The Cygnus Loop, of which the Veil is the brightest visible section, is roughly 1,470 light-years from Earth in the constellation Cygnus. This estimate comes from Hubble proper-motion measurements of the filaments. The entire loop spans about 3 degrees of sky.

The brighter segments, such as the Eastern Veil (NGC 6992) and the Western Veil (NGC 6960), can be glimpsed in a 4-to-8 inch telescope under dark skies using a narrowband filter. The Pickering's Triangle section is much fainter. The Witch's Broom is part of NGC 6960 near the star 52 Cygni.

The full Cygnus Loop spans roughly 110 light-years across the sky, making it one of the largest apparent supernova remnants visible from Earth. At its estimated distance, this corresponds to about six times the diameter of the full Moon. The shock front continues to expand and collide with interstellar gas.