EXTERNAL LINK ARTICLE
Sorry. I was wrong. Celestia DOES have this capability.
One of the nebula, with a slite 3d rotation it seems. Without looking at a collection of nebula pictures maybe 'Horse head'?
It CAN'T be a photographic gif. I don't think programs like Celestia has that much detail. Maybe just a drawing??
I think it may have been modeled in a 3D program, and the texture is placed on the object, with transparency settings and light diffuse settings, so the stars do not get darkened by shadow in the render, except for dark objects that is not open space which is set to be transparent.
Sorry, should really have chased this stuff up BEFORE posting.
Nah - it has made for some good discussion, :D