The UV variations of the symbiotic star CH Cygni from 1978 to 1981.

Abstract

The spectroscopic changes of CH Cygni from early 1978 to late 1981 are discussed with reference to several ultraviolet spectra obtained at the Villafranca Satellite Tracking Station. Correlations have been found to exist between the fluxes of the continuum and the fluxes of the forbidden and semiforbidden lines. Three new forbidden-line identifications are tentatively reported, and the physical mechanisms responsible for several emissions, including Fe II-lines, are discussed. The radial velocities of the circumstellar lines are discussed, together with their variations in time.