Long-term photometry of the asynchronous polar BY Cam: a period study.

Analysis of 15 yr of photometric monitoring of the asynchronous magnetic cataclysmic variable BY Cam leads to revised assignments of the periodicities in the system. The surprising stability of the 197.4-min period suggests that this is the orbital period. We confirm the 7.3-d beat period between the orbital period and the white dwarf spin period, and show that the observed periods of the orbit, spin and beat are consistent to within the errors. In earlier work, the 197.4-min period has been assigned to the sideband. Because of the observed stability of the 197.4-min period in our data, the synchronization time of BY Cam is >3500 yr (much larger than that in other asynchronous polars) if the earlier period assignments are adopted. We also suggest that ∼145-d periodicity seen in our data may be due to precession of the rotational pole of the white dwarf. [ABSTRACT FROM AUTHOR]