What a dreamy image! Otherworldly yet familiar like a twisted ribbon. You’re looking at a snippet of the Veil Nebula, a vast bubble of expanding gases from a supernova explosion that occurred about 8,000 years ago in Cygnus the swan. The original star was a supergiant about 20 times more massive than the sun. Long before it went kablooey it spewed gas and subatomic particles into space in powerful stellar winds, forming an enormous bubble of dilute material around itself.
Later, when the star self-destructed, the expanding shock wave slammed into the shell, heating and exciting the gas to glow. Even today, the nebula continues to balloon outward at 220 miles a second, a sight you can see with your own eyes in this animation made with the Hubble Space Telescope between 1997 and 2015. The nest-shaped nebula spans about 3 degrees or six full moons of sky. Where the gas is dense the shock wave creates bright filaments; where it’s thin the filaments are faint or non-existent. The Veil’s striking colors are generated by variations in the temperatures and densities of the chemical elements present. These include hydrogen, sulfur and oxygen.
The Hubble has a narrow field of view suitable for closeups of small sections of the Veil. To capture the entire supernova remnant you’ll need a telephoto lens and multiple time exposures. A 6-inch telescope will faintly show the brightest parts, dubbed the Eastern Veil and Western Veil. Larger telescopes equipped with an O III (oxygen-3) filter, which removes both natural and human-made light pollution, dramatically increases the nebula’s visibility, making it one of the sky’s most incredible sights. Maybe the most incredible outside our solar system.
On a dark night through my 15-inch telescope it’s thick with delicate filaments that remind me of skeletal fingers and ribs. Nothing else compares. Most amateurs make the Veil a routine stop every summer and fall. It’s easy to spend an hour or longer here exploring a multitude of fine structure that reveals itself to the patient eye. Some of us like to imagine the fury of the initial explosion which occurred around the year 6,000 BC., more than 3,000 years before the first pyramids were built.
Assuming the blast wasn’t hidden by dark clouds of interstellar dust it must have been a singular event, perhaps glowing brighter than Venus and casting shadows at night. What thoughts and feelings did it inspire in our distant ancestors? Amazement, anxiety and curiosity I’d bet. The same sensations we still experience while sorting through its remains 8,000 years later.