Saturday, October 13, 2007
This large planetary nebula is known as the Helix Nebula. It is very large (as big as the full moon), but is notoriously difficult to see without a very wide-field scope. It is so large, because it is the closest object of this type to the earth. It remains dim to our eyes, because the light is spread out over a larger area than the typical planetary nebula, in turn lowering the surface brightness. If it were farther away, the light would be more concentrated, and we would see it a bit easier.
This nebula is composed of gas and dust thrown off by a dying star. It is called the Helix because high detail images show two shells of gas resembling a vague helix shape. It is assumed the two shells were created by perturbations in the orbit of the star caused by an unseen companion.
I shot this image using my Canon 300D DSLR and my 10" Schmidt-Newtonian telescope.