We present a study of the cataclysmic variable star PT Per based on archival XMM-Newton X-ray data and new optical spectroscopy from the WHT with ISIS .
The X-ray data show deep minima which recur at a period of 82 minutes and a hard , unabsorbed X-ray spectrum .
The optical spectra of PT Per show a relatively featureless blue continuum .
From an analysis of the X-ray and optical data we conclude that PT Per is likely to be a magnetic cataclysmic variable of the polar class in which the minima correspond to those phase intervals when the accretion column rotates out of the field of view of the observer .
We suggest that the optical spectrum , obtained around 4 years after the X-ray coverage , is dominated by the white dwarf in the system , implying that PT Per was in a low accretion state at the time of the observations .
An analysis of the likely system parameters for PT Per suggests a distance of \approx 90 pc and a very low-mass secondary , consistent with the idea that PT Per is a “ period-bounce ” binary .
Matching the observed absorption features in the optical spectrum with the expected Zeeman components constrains the white dwarf polar field to be B _ { p } \approx 25 - 27 MGauss .