IUE observations of the high-velocity symbiotic star AG Draconis. II.The spectral variations during 1979-1983.

High quality IUE spectra of AG Dra gathered during 1979-81 were examined in concert with data taken at VILSPA. Visual bursts were detected in 1980 and 1983 and were associated with order of magnitude changes in the UV continuum and emission lines. Variability was persistent in the UV and He II lines after the bursts while the C IV line displayed small variations and the N V line was nearly constant. A binary system is indicated, composed of a nonvariable K-giant and a dwarf companion which accretes matter from a cooled stellar wind. The variability would arise from an extended region near the cool star heated by UV or X ray radiation from the giant. A wider range of spectral data are required to flesh out the physical processes of the accretion region, which may be a disk.