When a massive star dies in a supernova explosion, its gases are ejected in all directions into space. Eventually, the gas may condense and combine with interstellar hydrogen to create new stars. But long before that happens, we can glimpse snapshots of how such explosions change as they age by studying objects at various phases of evolution.
Supernova 1987A in the Large Magellanic Cloud is in the earliest years of such an explosion. In time, a compact expanding region of stellar debris looks something more like the Crab Nebula (M1). And after a few thousand years of further expansion, the gas becomes tenuous and you get a remnant cloud like the Veil Nebula.
Between 1,410 and 2,100 light-years away (sources disagree), the Veil Nebula and associated Cygnus Loop form one of the closest supernova remnants to the Sun. (Two in Vela and one in Orion are closer.) Its gas has moved outward 65 light-years in every direction since its progenitor — a star about 20 times the Sun’s mass — exploded about 10,000 years ago.
William Herschel, the father of deep-sky observing, discovered the Veil Nebula — or, at least, part of it. He first noted NGC 6960, the segment behind 52 Cygni, now called the Western Veil. Since then, astronomers have named and cataloged the other scattered pieces that make up this single large remnant. The Eastern Veil is NGC 6992 and NGC 6995, with an extension designated IC 1340. In between the main arcs in the nebula are three concentrations of brightly glowing gas: Pickering’s Triangle (discovered by astronomer Edward Charles Pickering’s assistant, Williamina Fleming), NGC 6974, and NGC 6979.
Also called the Cirrus Nebula, the Veil is large (about 3° wide) and bright enough to be seen with binoculars under skies free from light pollution. It looks wonderful in any optics, provided they have either a field wide enough or an aperture large enough to resolve the wispy filaments. An OIII filter really brings out detail and is especially useful when light pollution is an issue.
Make sure to explore Astronomy’s full list of 101 cosmic objects you must see. New entries will be added each week throughout 2022.
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