Well Celts studied the skies as part of the Pagan Religion, obviously the heavens were a big deal for them, I'd have to agree the Roman's interest in the stars, would be more weather related than anything. But of course I could be wrong! I watched an interesting show called Secrets of the Dark Ages, where they basically explore the role, and important contributions of so-called 'barbarians'. Even though It's called Secrets of the Dark Ages many of the episodes cover roman times. I must say after watching that show I begin to wonder exactly how much the romans thought of themselves!