Anomalous ultraviolet line flux ratios in the cataclysmic variables 1RXS J232953.9+062814, CE 315, BZ Ursae Majoris, and EY Cygni, observed with the Hubble Space Telescope space telescope imaging spectrograph

Brief Hubble Space Telescope Space Telescope Imaging Spectrograph spectroscopic snapshot exposures of the cataclysmic variables 1RXS J232953.9+062814, CE 315, BZ UMa, and EY Cyg reveal very large N v/C IV line flux ratios, similar to those observed in AE Aqr. Such anomalous line flux ratios have so far been observed in 10 systems and presumably reflect a different composition of the accreted material compared to the majority of cataclysmic variables. We discuss the properties of this small sample in the context of the recent proposal by Schenker et al. that a significant fraction of the present-day population of cataclysmic variables may have passed through a phase of thermal timescale mass transfer.