Polarimetry of the eclipsing polar RX J0929.1 - 2404
Monthly Notices of the Royal Astronomical Society, Volume 295, No. 4, Year 1998
Notification
URL copied to clipboard!
We report polarimetric, spectropolarimetric and photometric observations of the eclipsing ROSAT cataclysmic variable RX J0929.1 - 2404, which confirm that the system is a new polar (AM Herculis system). This brings the number of eclipsing polars to nine, with RX J0929.1 - 2404 being only the third such system above the period gap. Circular polarization variations from ∼ -20 to 10 per cent are seen over the 3.39-h orbital period, with a minimum around the time of eclipse. The photopolarimetric data were modelled using arc-shaped cyclotron emission regions in a centred dipole geometry. Results imply that RX J0929.1 - 2404 is a 'two-pole' system, with one emission region partially visible at all orbital phases. Spectropolarimetry observations show some evidence for the presence of cyclotron humps in the continuum, with spacings consistent with a magnetic field strength of ∼20 MG. Photometry of the eclipses provides information on the size of the emission region, which is consistent with a hotspot on the surface of the white dwarf. The eclipse duration implies an inclination in the range 70°≲i≲78°.