In this paper the authors provide preliminary results of multifrequency observations of BF Cyg carried out in July 1986.

During the summer seasons of the years 1977 to 1985 daily velocity measurements of solar global oscillations have been obtained using a resonant scattering spectrometer. After calculating the power spectra of the daily residuals, the mean for each season is found. Several discrete frequency intervals are defined in the spectrum. The mean power in

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From the analysis of radial velocity measurements of the Sun, obtained at Izaña from 1976 to 1985, stable periods longer than 1 day, have been found in the observed signal. The appearance of an oscillation with a 13 day period has been confirmed. The comparison, for 1981 - 84, of the observations with a calibrated numerical model of the passage of

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