A unique symbiotic-like/cataclysmic triple star 4 Dra (=CQ Dra): six years of UBV monitoring

The bright (mv ≈ 5) M3III star 4 Dra (HD108907, HR4765, CQ Dra) is a unique triple system combining in itself the basic structural properties of a symbiotic-like binary and of a cataclysmic one. The red giant 4 Dra A forms a wide binary (Porb ≈ 1703 d) with a hot companion 4 Dra B which seems to be a compact cataclysmic binary system (4 Dra BC, probable Porb of about 4 h).We have monitored the 4 Dra system in UBV at the Skalnaté Pleso and Starà Lesna Observatories and at the Tartu Astrophysical Observatory during a total of 205 nights between 1989 March 12 and 1995 June 20; a few additional data points were obtained at the Bucharest Observatory.