Infrared and radio observations of the Of stars HD 108, HD 14947, HD 16691, HD 47129 are reported. They confirm the presence of thermal stellar wind emission with mass loss rate 1 - 2×10-5M_sun;y-1. The radio variability on time scale of months of the Of star Cyg OB2 No.5 is shown. This variability is not correlated with the 10 micron excess.

Infrared and V band photometry of the RS CVn system II Peg, carried out in 1984 and 1986, has been analysed with a simple model in order to follow the evolution of the activity of spots over the surface of the visible star. The group of spots has been concentrated in longitude from 1984 to 1986 covering about 27% in 1984 and 44% of the visible disk

An analysis of full disc line of sight velocity data yield line splitting values of the low l-value non-radial modes. Possible variations of the line splitting with the solar cycle are investigated.

Monitoring of active late-type dwarfs, spectroscopically with high resolution (λ/Δλ ≡ 105) and high S:N (>300) round their activity cycles, principally in the Ca II H resonance line, offers techniques to explore, (1) plage filling factors, (2) 3-dimensional chromospheric velocity fields, (3) maps of surface activity via "Doppler Imaging". In this

High resolution bidimensional optical spectroscopy in H-alpha line, N II forbidden line at 6548 and 6583 A, and S II forbidden line at 6717 and 6713 A, of the bipolar nebula S 106 are reported. The resulting H-alpha velocity maps show strong variations in the emission line profiles along the nebula, a situation which is duplicated in other lines

High signal to noise spectra are required in chromospheric modelling because chromospheric emission lines are formed in a boundary layer under conditions of NLTE and in non-hydrostatic equilibrium, as well as in multiple magnetically-controlled streams, with horizontal structure on several scales, and vertical velocity fields. To obtain useable