Simultaneous Extreme Ultraviolet and Optical Observations of the Magnetic Cataclysmic Variable PQ Geminorum

We present the results of simultaneous optical polarimetry and EUV spectroscopy and photometry of PQ Gem, a magnetic cataclysmic variable which shows observational properties of the strongly magnetic AM Her class, as well as the weaker field DQ Her stars. The EUV spectrum of PQ Gem is weak, showing continuum blueward of 80 Å and a few possible weak emission lines due to Mg, Si, and Ne. The EUV light curve has a similar appearance to previous X-ray data obtained for PQ Gem, including a narrow ``dip'' feature that is modulated with the white dwarf spin period. Observed polarization variations on the spin period, modeled by a slightly modified version of that used in Potter et al., matched the optical light curve and linear polarization curve reasonably well, but not the position angle variation. The EUV properties of PQ Gem can also be understood in the context of this model.