A cataclysmic binary that has undergone repeated outbursts similar to those found in novae. Five or six stars are assigned to this class but only two, T Coronae Borealis (the Blaze Star) and RS Ophiuchi, have much in common, giant secondaries and long orbital periods (227.6 and c.456 days respectively). These two stars appear to be similar to an RR Telescopii star or symbiotic nova.