A Systematic Search for Short Orbital Period Cataclysmic Variables Using the Zwicky Transient Facility

We report a new search for short period cataclysmic variables using data from the Zwicky Transient Facility (ZTF). We selected all objects with G<19.5 from the Gaia white dwarf catalog (Gentile Fusillo et al. 2021) and searched for ZTF lightcurves with periodic signals between 1 and 2 hours, with the goal of finding short period cataclysmic variable stars. We developed a new period-finding Python code and processed 124,819 lightcurves. Our code was able to extract periods even for stars with relatively sparsely sampled photometry that exhibited extreme variations in their brightness over time. Out of this sample, 235 objects show a clear periodic signal in the range of 1-2 hrs, out of which 176 are new CVs or other classified variables. We attempted to classify each object based on the lightcurve shape, Gaia parallax, Panstarrs and WISE colors, and identified 50 high-confidence CV candidates. Other objects include pulsating white dwarfs, rotating white dwarfs and detached reflection and ellipsoidal white dwarf binary systems. We present color magnitude diagrams showing the locations of our new variables and example spectra.