Over observing is no big problem! You have a much bigger effect of different between observers: Weather condition, Type of telescope, Magnification, Latitude, And the DJUNGEL of : Different of comparing stars, Different in use of star catalogue, Expertness of observer, ligtnings of sky etc. If you are looking for a nice and beautiful light curve, yes you can only use your one observations and with a period about 7 days between observations and always in same conditions.... Maybe. And how wants to have a nice and beautiful light curve? "You don't now what you don't see" Regards Hans-Goran