Optical and Ultraviolet Activity in RT Lacertae During 1985 and 1986

Abstract

Continued monitoring of optical spectra of RT Lac, a peculiar RS CVn system, showed a large range of activity in the H-alpha line. At times, there was no excess emission or absorption, and at others, much. During active times, the excess emission varied greatly with phase and seemed to come from an extended region. Two UV observations, taken contemporaneously with optical spectra, also showed strong variations in the emission-line strengths. The data are consistent with intermittent mass transfer and imply that RT Lac is similar to other objects which have transient disks.