POLARIZATION IN THE HIDDEN POLE AM HER SYSTEM EXO-032957-2606.9

We report the detection of circular polarization in the proposed AM He r system EXO 032957-2606.9, thus confirming its membership of the clas s. The polarization is approximately constant at similar to - 6 per ce nt, independent of orbital phase. This indicates that the system is se en at low inclination, and lends support to a model in which the main accreting pole is in the lower hemisphere of the white dwarf and hidde n behind the limb. The detection of polarized flux from the visible po le is a result of the low state of the system, which reduces the dilut ion from the dominant pole stream flux.