CR Boo: the 'helium ER UMa star' with a 46.3-d supercycle

We observed the unique helium cataclysmic variable CR Boo (=PG 1346+082) extensively, using CCD and visual photometry, during the period 1995-1998. The observation revealed the existence of a quasi-periodic alternation of bright and faint states with a period of 46.3 d. During the faint states, the system shows short outbursts with a characteristic recurrence period of 4-8 d. The 1490-s signal, which has been considered as superhumps, almost disappeared during the short outburst on 1998 January 2. The overall patterns of outbursts and the appearance of the superhump signal are remarkably similar to those of hydrogen-rich ER UMa stars. We propose CR Boo as a member of a class of 'helium' counterparts of ER UMa stars.