V1500 Cygni

V1500 Cygni is a double system in the constellation Cygnus consisting of a star and a white dwarf in a close orbit, which is classified as an AM Herculis system.

The system seemed to end of August 1975 as Nova Cygni 1975, a visible with the naked eye Nova, the maximum brightness of 2.2 mag reached. She was thus one of the lightest and fastest novae that have been observed in the 20th century. In 1995, the visual magnitude was approximately 18 likes dropped. V1500 Cygni was the first Nova that the strongly magnetic cataclysmic variables (CVs ) of the type AM Herculis ( Polar) could be assigned. It has been shown that the characteristic in these systems coupling between rotation period of the white dwarf and the orbital period is canceled due to the nova outburst. The rotation period of the white dwarf is currently 3.5 minutes shorter than the orbital period of the binary star of 201 minutes, but synchronized on a time scale of about 150 years with the orbital period. V1500 Cygni is thus one of the four known asynchronous AM Herculis stars ( alongside BY Cam, V1432 Aql and CD Ind).