This star, 20 times bigger than or sun, blew up about 8000 years ago.
Called the Veil Nebula, the debris is one of the best-known supernova remnants, deriving its name from its delicate, draped filamentary structures. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan.
In this image, red corresponds to the glow of hydrogen, green from sulfur, and blue from oxygen. The bluish features, outlining the cavity wall, appear smooth and arched in comparison to the fluffy green and red structures. The red glow is from cooler gas that was excited by the shock collision at an earlier time and has subsequently diffused into a more chaotic structure. A few thin, crisp-looking, red filaments arise after gas is swept into the shock wave at speeds of nearly 1 million miles an hour, so fast that it could travel from Earth to the moon in 15 minutes.