Light curves can be periodic, as in the case of eclipsing binaries, cepheid variables and other variables, or aperiodic, like the light curve of a nova, a cataclysmic variable star or a supernova.
The study of the light curve, together with other observations, can yield considerable information about the physical process that produces it or constrain the physical theories about it.
wikipedia.org dumped 2003-03-17 with terodump