I'm reading Nick Strobel's astronomy notes. I should mention that it's an excellent website for an amateur like me. I can't get one thing right though. He mentions about fixed coordinates of stars measured in RA (right-ascension) and declination. He says that "Earth's rotation is broken up into 24 hours, so one hour of RA = 15 degrees of rotation" but does not mention if RA is divided into 24 hours. The same source says that stars take 23 hours and 56 minutes to make full rotation around an observer (or more exactly the earth revolves around its axis in 23 hours and 56 minutes). Doesn't this mean any star with 23 hour and 58 minutes right ascension has actually RA of 2 minutes (23 hour and 58 minutes minus 23 hours and 56 minutes=2 minutes)? Should we not divide RA into 23 hours and 56 minutes instead of 24 hours?