Spin periods and accretion disc structure in CV.s below the period gap

Our XMMNewton observations of dwarf nova OY Car have revealed a possible WDspin period at 0.41 of the orbital period (Ramsay et al. 2001a). Now we plan to observe a set of other dwarf novae below the period gap in order to searchfor WD spin periods. If they are detectable in Xrays, it immediatedly impliesthat the white dwarfs in these systems are at least weakly magnetic. This wouldextend the spectrum of magnetic CV.s into even weaker field systems than theintermediate polars. We will also use our accretion disc structure modellingcodes, together with combined Xray and OM light curves, to retrieve informationon the 3D structure of the discs in these systems. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]