Orbital studies of cataclysmic binaries. I - AB Draconis and WW Ceti

The authors present time-resolved spectroscopy of two cataclysmic binary systems, AB Draconis and WW Ceti, to determine their binary periods and other dynamical information. They describe their methods of data acquisition, reduction, and analysis in some detail. The most novel feature is a Monte Carlo technique for determining the probability of cycle-count alias errors, a perennial problem in this sort of work. The authors find the period of AB Draconis to be 0.1520 day, and that of WW Ceti to be most probably 0.1758 day, though a cycle-count alias at 0.1495 is possible. The velocity amplitudes they obtain suggest that both systems have rather low orbital inclinations.