The metallic abundances in the polar BY Cam

The source BY Cam is unique among all highly magnetized cataclysmic variables (polars) in showing a significant asynchronism between rotation and orbitalperiods and very peculiar C and N emission line ratios in the UV, suggestingabnormal CNO abundances. Recent FUSE observations in the far UV have now alsorevealed the weakness of the resonance OVI line. The origin of this verypeculiar line spectrum is unknown. BY Cam may indeed represent a key systemfor our understanding of CNO enrichment and nova phenomenon onto magnetizedwhite dwarfs. We propose to observe the source with XMM to derive for the first time a detailed Xray line spectrum with RGS reaching the importantmetallic lines and to follow its variability with EPIC.\\\\ truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]