Location of Repository

Simultaneous EUV and IR Observations of the Eclipsing Polar HU Aqr

By Steve B. Howell, David R. Ciardi, Martin M. Sirk and Axel D. Schwope

Abstract

Submitted to AJ – 2 – We present simultaneous EUV and infrared (J,K) observations of the polar HU Aqr obtained during August 1998 when the star was in a high mass accretion state. EUV and IR light curves and EUV spectra are presented and compared with previous observations. The accretion region on the white dwarf has increased in temperature (124,000K to 240,000K) and radius (0.04 RWD to 0.06 RWD) compared with previous EUV observations made during low mass accretion states. The EUV and IR photometric observations are shown to have a similar appearance as a function of orbital phase. The EUV photometry shows rapid changes and provides evidence for mass accretion via blobs. The high state IR light curves present an asymmetric double-humped shape with J=14.8 and K=14.1. We applied an ellipsoidal model fit to the observations and the result indicates that the cause of the modulated shape is both due to ellipsoidal variations from the Roche Lobe filling secondary star and a complex flux combination probably dominated at all orbital phases by cyclotron emission. The source of maximum cyclotron emission appears to be in the accretion column high above the white dwarf surface

Topics: Received, accepted
Year: 2001
OAI identifier: oai:CiteSeerX.psu:10.1.1.317.5350
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://citeseerx.ist.psu.edu/v... (external link)
  • http://arxiv.org/pdf/astro-ph/... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.