If my understanding is correct, Chury, the best explored comet so far is rather on the smallish side as comets go. Most comets observable with naked eye were so because they flew close to Earth, not because they were so big. I wonder, though, how big are the biggest ones.
Let's get it in two variants:
- How big is the biggest known comet? (mass, diameter)
- Is there an estimate, or a theoretical limit on how big a comet can be? (for whatever reason, e.g. becoming a planet, breaking up due to tidal forces or whatever)