UBVRI photopolarimetry of the long period eclipsing AM Herculis binary V1309

Abstract

We report simultaneous UBVRI photo-polarimetric observations of the long period (7.98 h) AM Her binary V1309 Ori. The length and shape of the eclipse ingress and egress varies from night to night. We suggest this is due to the variation in the brightness of the accretion stream. By comparing the phases of circular polarization zero-crossovers with previous observations, we confirm that V1309 Ori is well synchronized, and find an upper limit of 0.002 percent for the difference between the spin and orbital periods. We model the polarimetry data using a model consisting of two cyclotron emission regions at almost diametrically opposite locations, and centered at colatitude 35 (deg) and 145 (deg) on the surface of the white dwarf. We also present archive X-ray observations which show that the negatively polarised accretion region is X-ray bright.

arXiv comment11 pages, 12 figures (2 colour), Fig1 and Fig 4 are in lower resolution than in original paper, accepted for publication in Monthly Notices of the Royal Astronomical Society

References in corpus (7)

• On the late spectral types of cataclysmic variable secondaries
• High-Speed Energy-Resolved STJ Photometry of the Eclipsing Binary UZ For
• Time-Resolved HST Spectroscopy of Four Eclipsing Magnetic Cataclysmic Variables
• System parameters of the long-period polar V1309 Ori
• The Short Period Supersoft Source in M31
• STJ Observations of the Eclipsing Polar HU Aqr
• The Long Period AM Her-like Cataclysmic Variable RXJ051541+0104.6

Cited by in corpus (4)

• Circular polarization survey of intermediate polars I. Northern targets in the range 17h<R.A.<23h
• XMM-Newton observation of the long-period polar V1309 Ori: The case for pure blobby accretion
• Implications of the Universal Temperature Profile for Galaxy Clusters
• The secondary star and distance of the polar V1309 Ori