Two new ROSAT discovered high field polars: RXJ2022.6−3954 in Sagittarius and RXJ0132.7−6554 in Hydrus

We report the discovery of two new AM Herculis systems (polars), identified as the optical V∼19 mag and V∼20 mag counterparts of the soft X-ray sources RX J2022.6−3954 and RX J0132.7−6554 detected during the ROSAT All-Sky Survey and present the results of our optical and X-ray follow-up observations. From the cyclotron emission lines detected in the optical spectra we determine magnetic field strengths in the accretion region ofB = 67(2) MG for RX J2022.6−3954 and B = 68(2) MG for RX J0132.7−6554. With Porb = 78.0176(4) min for RX J2022.6−3954 and Porb = 77.831(8) min for RX J0132.7−6554 both objects have orbital periods which lie at the lower limit of the period distribution of CVs. RX J0132.7−6554 is the shortest period polar yet detected. Both objects show no eclipse by the secondary stars, and, therefore must have orbital inclinations of i <∼ 85◦. As RX J2022.6−3954 shows a dip due to the accretion stream crossing our line-of-sight and the accretion region on the white dwarf is partially self-eclipsed we can further constrain the orbital inclination and co-latitude of the magnetic pole to be 45◦ < i < 85◦ and 45◦ > δ > 5◦. From the absence of M-star features in the faint phase spectra of both objects we obtain a lower limit for the distance to RX J2022.6−3954 of d > 190 pc and to RX J0132.7−6554 of d > 300 pc . The high magnetic fields and short orbital periods make both objects highly interesting in the context of the evolution of accreting close-binary systems.