Open AccessSTJ observations of the eclipsing polar HU Aqr
Author(s) -
Bridge C. M.,
Cropper Mark,
Ramsay Gavin,
Perryman M. A. C.,
De Bruijne J. H. J.,
Favata F.,
Peacock A.,
Rando N.,
Reynolds A. P.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05841.x
Subject(s) - physics , white dwarf , astrophysics , cataclysmic variable star , accretion (finance) , brightness , polar , intermediate polar , astronomy , magnetic field , eclipse , telescope , stars , quantum mechanics
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 William Herschel Telescope in 2000 October, providing high signal‐to‐noise ratio 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 occurring on to 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.