RX J0744-52: a probable new intermediate polar

Abstract

We present optical and X-ray data of the cataclysmic variable RX 0744-52 discovered using ROSAT by Motch et al. High-resolution spectroscopy centred on the Hα line indicates a probable orbital period of 3.60 h. From its distance (obtained using polarimetry), its X-ray luminosity, its X-ray colour and its X-ray/UV+optical ratio, we suggest that RX 0744-52 is a new intermediate polar. The absence of a significant coherent modulation in the X-ray light curve suggests either that RX 0744-52 has a low inclination or that the rotational and magnetic axes must be closely aligned. This is consistent with its small radial velocity amplitude.

accretion, accretion discs, stars: individual: RX J0744-52, novae, cataclysmic variables, white dwarfs, X-rays: stars