Variability of the Spin Period of the White Dwarf in the Intermediate Polar V405 Aur
We present the results of photometric CCD observations of the magnetic cataclysmic variable V405 Aurigae obtained using different instruments. We analysed variability of the spin period of the white dwarf in the V405 Aur system using our observations and previously published maxima timings. The spin period of the system in 2010-2012 is P=545.4558163(94)s. As we have gaps in observational data, we present 2 hypotheses of the spin period variability of this system - a cubic ephemeris which may be interpreted by a precession of the magnetic white dwarf or a periodic change with a period of 6.2 years and semi-amplitude of 17.2\pm1.8 sec. The periodic variations may be interpreted by a light-time effect caused by a low-mass star. In this case, the system belongs to a rare class of cataclysmic variables with a third body.
Image credit Mark Garlick