STJ Observations of the Eclipsing Polar HU Aqr

Abstract

We apply an eclipse mapping technique to observations of the eclipsing magnetic cataclysmic variable HU Aqr. The observations were made with the S-Cam2 Superconducting Tunnel Junction detector at the WHT in October 2000, providing high signal-to-noise observations with simultaneous spectral and temporal resolution. HU Aqr was in a bright (high accretion) state (V=14.7) and the stream contributes as much to the overall system brightness as the accretion region on the white dwarf. The stream is modelled assuming accretion is occuring onto only one pole of the white dwarf. We find enhanced brightness towards the accretion region from irradiation and interpret enhanced brightness in the threading region, where the ballistic stream is redirected to follow the magnetic field lines of the white dwarf, as magnetic heating from the stream-field interaction, which is consistent with recent theoretical results. Changes in the stream eclipse profile over one orbital period indicate that the magnetic heating process is unstable.

Accepted for publication in MNRAS (11 pages)

References in corpus (5)

• An Exploration of the Paradigm for the 2-3 Hour Period Gap in Cataclysmic Variables
• High-Speed Energy-Resolved STJ Photometry of the Eclipsing Binary UZ For
• Direct determination of quasar redshifts
• Accretion Stream Mapping of HU Aquarii
• Analysis of astronomical data from optical superconducting tunnel junctions

Cited by in corpus (12)

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• Detection of a planetary system orbiting the eclipsing polar HU Aqr
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• Hunting high and low: XMM monitoring of the eclipsing polar HU Aquarii
• Testing the planetary models of HU Aquarii
• Variability of the Accretion Stream in the Eclipsing Polar EP Dra
• A Concept for an STJ-based Spectrograph
• High-speed, energy-resolved, STJ observations of the AM Her system V2301 Oph
• XMM-Newton observations of the eclipsing polar EP Dra
• Temperature determination via STJ optical spectroscopy
• UBVRI photopolarimetry of the long period eclipsing AM Herculis binary V1309
• Accretion stream mapping with genetically modified "fire-flies"