How close does a Biata need to get to a celestial circle to be uncomfortable? I'm sure there's no hard-set rule, but I figure that people who've been around longer than I have likely have some experience on the subject. Does it vary by the strength of the circle?
It's not hard set. I used to start getting extra irritable and irrational within about 10 feet of the building where I knew it was, then start acting gradually like I was getting hit with a Drain the closer I got to it.
I never really treated strength of circle as any difference. And whenever someone later pointed out that X magic I was around (which was a general spell) was celestially cast, I'd just shrug at them and verbally chalk it up to being general aspect magic.