That really is the sun, but the background is a water colour... This is a photo-blog, so let me show you how this was done:

I started out with a simple half white, half blue water colour:



Using a crappy old telescope with the eyepiece out, I projected the image of the sun onto the page and rotated it 180 degrees... This picture should make it clear:



Of course most people seem to like the real sunset that night, but no one said "art" was pretty...