  We have made a series of snap-shot observations of 37 polars using
XMM-Newton. We found that 16 of these systems were in a low, or much reduced,
accretion state. Of those, 6 were not detected in X-rays. This suggests that in
any survey of polars, around half will be in a low accretion state. We tested
if there was a bias towards certain orbital periods: this is not the case. Of
the 10 systems which were detected at low, but significant rates in X-rays, 8
showed significant variability in their X-ray light curves. This implies that
non-uniform accretion still takes place during low accretion epochs. The
bolometric luminosity of these systems is ~10^30 ergs s, two orders of
magnitude less than for systems in a high accretion state. The X-ray spectra
show no evidence of a distinct soft X-ray component. However, the X-ray and UV
data imply that such a low temperature component exists: its temperature is low
enough for its flux distribution to move outside the bandpass of the X-ray
instruments.

Astrophysics