The Polar Catalysmic Variable 1RXS J173006.4+033813

We report the discovery of 1RXS J173006.4+033813, a polar cataclysmic variable with a period of 120.21 minutes. The white dwarf primary has a magnetic field of B = 42^(+6)_(-5) MG and the secondary is an M3 dwarf. The system shows highly symmetric double-peaked photometric modulation in the active state as well as in quiescence. These arise from a combination of cyclotron beaming and ellipsoidal modulation. The projected orbital velocity of the secondary is K_2 = 390 ± 4 km s^(–1). We place an upper limit of 830 ± 65 pc on the distance