[andrewflnr]

If you're sufficiently cynical, you can describe almost all astronomy results that way. Lots of alternate explanations for the observations have been proposed, and fail to match the full evidence.

Just how much evidence are you going to demand of phenomena hundreds of lightyears away before you say, "yeah, that's probably what it is"? Anyway, do be sure to read the whole list of observations linked above by csours, as there are quite a few.