The Veil Nebula

Today, instead of pictures of spiders and caves, I have a picture of the lovely celestial object known as the Veil Nebula. Now, I'll have to be more precise than that: you see, the Veil Nebula as a whole refers to a humongous supernova remnant about 1,470 light-years away in the constellation Cygnus, the Swan. This nebula is quite large: it can be traced for almost 3 degrees in the sky, making it 6 times wider than the full Moon (and about the width of the Andromeda galaxy), while covering 36 times the area. Because it is such a diffuse ball of gas spread over such a large area (nearly a hundred light-years), it is easiest to see around the edges.

There are a few places where those edges are thicker and easier to see, and it is one of those edges that I have for you to see today. This part is known as the Western Veil nebula, and is one of the two brightest portions of the nebula. Because the nebula is so tremendously huge on the sky compared to most objects, different parts of it have actually been assigned their own numbers in the New General Catalogue (NGC). This part is known as NGC 6960.

The Western Veil Nebula, NGC 6960, in Cynus. The bright star is an unrelated foreground star, 52 Cygni.

So in this picture, you can see part of the outer arc of the supernova remnant where it's a bit thicker than average. The original explosion site was to the right and slightly below this picture, and if you look closely to the right of the bright part of the nebula you can see very faint and wispy filaments of gas. The nebula looks sort of purple-ish to me; the blue light comes from doubly-ionized oxygen, and I suspect that the red light is your basic hydrogen-alpha.