A new magnetic cataclysmic variable: WGA J1047.1+6335

Abstract

A new ultrasoft X-ray source, WGA J1047.1+6335, was discovered during a search of the ROSAT PSPC pointed observations, data from which are publicly available (White, Giommi, & Angelini; Singh et al.). We identify the X-ray source with an optical object of V≃19.4 mag in the error circle of the X-ray source position. Optical and X-ray photometry has revealed the presence of an ~40 minute period. Strong emission lines of H and He have been detected in its optical spectrum. The X-ray spectrum of WGA J1047.1+6335 is best fitted with a blackbody (kT≃40-50 eV) with negligible interstellar absorption and no X-rays with energies greater than 0.5 keV. Polarimetry shows a high amplitude (20% circular polarization) variation on an 80 minute timescale. These properties all suggest a polar with an 80 minute orbital period and either beaming/self-eclipsing effects from one pole or nearly equal emission from two poles.