Within the framework of a large campaign of coordinated multifrequency observations of the T-Tauri Star RU Lupi, we present simultaneous UV, optical and IR energy distributions secured in the years 1984-86. The observations have been carried out with lUE satellite and ESO optical and IR telescopes. Strong variations on different time-scales have been detected in UV and optical regions. On June 30, 1986 a large flare was observed. An analysis of the different energy distributions indicates that the variability of RU Lupi is mainly due to a strong activity in the surface layers of the star.
High resolution UV spectroscopic observations of the binary symbiotic star AG Peg obtained with the IUE satellite in the periode 1978-81 are analyzed. The variability of the fluxes and the radial velocities of emission lines accordingto orbital phase are presented, The observaions support a binary model with mass transfer from a hot rotationaly unstable subdvarf to a cool M giant.