2000A&A...358L..45R

We present time resolved spectroscopy of the newly discovered magnetic CV HS 0922+1333. Our observations show that it has a period of 244±2min. Its optical spectra are dominated by a strong single spot cyclotron line at 5334Å. A detailed analysis shows that further cyclotron harmonics are at 7800Å (hidden by the M dwarf companion) and at 4034Å which yields a field strength of 66 MG (n=2, 3 and 4). A much weaker spot appears to be present at antiphase with B≃81MG (n=2 and 3 visible). HS 0922+1333 does not show any emission lines (like Balmer, HeII) except the cyclotron harmonics. It has an extremely low accretion rate of the order of 3x10^–13M_☉/yr, atypical for its long period. It has not been detected by ROSAT. HS 0922+1333 is the third member of a class of strong cylotron line emitters (low accretion rates) defined by HS 1023+3900 and 1RXS J012851.9-233933, both probably in the CV period gap, while HS 0922+1333 is clearly above the period gap. At a distance of 190pc the WD primary is rather faint (M_B=12.6) and cool (T_eff≤10000K) implying the system is old.