RR Tau is a Young Stellar Object with a GCVS classification of INSA. It is also classified with the Herbig Ae/Be stars. See here. The object is always active, and is an excellent star to observe if you have a 20cm telescope or larger. Variations can be in the order of one magnitude in 24 hours, or several weeks with smaller fluctuations.
See here for details of the BAAVSS observing project.