1RXSJ062518.2+733433: A new intermediate polar

Abstract

We report the identification of the cataclysmic variable 1RXSJ062518.2+733433 as an intermediate polar. The orbital period of the system is determined to be 283.0+-2 min from the radial velocity variation of Halpha, measured in an extensive set of time-resolved spectroscopy. Differential optical photometry obtained over a base line of three weeks reveals the presence of coherent variability with a period of 19.788+-0.002 min, which we suggest to be the white dwarf spin period. The power spectrum of our photometry also contains a strong signal near the spectroscopically determined orbital period. The emission lines in 1RXSJ062518.2+733433 display a complex multicomponent structure. In the trailed spectrogram of HeI 6678 we detect a narrow component with a radial velocity semi-amplitude of ~140kms, consistent with a possible origin on the irradiated face of the secondary. The absence of eclipses gives an upper limit on the binary inclination of i<=60deg.