Abstract
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°.
Original language | English |
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Pages (from-to) | 899-906 |
Number of pages | 8 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 295 |
Issue number | 4 |
Publication status | Published - 21 Apr 1998 |
Keywords
- 2404
- Accretion, accretion discs
- Novae, cataclysmic variables
- Stars: individual: RX J0929.1
- Stars: magnetic fields
- White dwarfs
- X-rays: stars