Constant, thanks for the detailed reply. After considering the evidence you presented, I now agree that at least one (out of fifteen?) of the charges that he was on trial for had to do with his astronomical theories. Also, I am very surprised to learn that one of his charges was that he thought Jesus was rightfully "hanged" for being a deceiver.

I'll see if I can hunt down a decent source on whether or not he was actually convicted of the fifth charge.