Hubble Space Telescope eclipse observations of the nova-like cataclysmic variable UX Ursae majoris

摘要

We present and analyze Hubble Space Telescope observations of the eclipsing nova-like cataclysmic variable UX UMa obtained with the Faint Object Spectrograph. Two eclipses each were observed with the G160L grating (Covering the ultraviolet waveband) in 1994 August and with the PRISM(covering the near-ultraviolet to near-infrared) in November of the same year. The system was ～50/100 brighter in November than in August, which, if due to a change in the accretion rate, indicates a fairly substantial Increase in M_acc by > ≈ 50/100. The eclipse light curves are qualitatively consistent with the gradual Occultation of an accretion disk with a radially decreasing temperature distribution.