We present some preliminary results of a time-resolved spectroscopic study of the peculiar cataclysmic system AM CVn. The analysis of He i lines profile variability, suggests the existence of a 1051 s periodicity. This is one of the known photometric periods, candidate to be the orbital period of the system, or the rotational period of the primary.

Visible light curves of the RS CVn short-period system BH Vir, collected over 26 years, have been analyzed.B-V colours indicate that the primary minimum is normally redder than one would expect, assuming the spectroscopic classification of the system components, while the secondary yielded bluer. A qualitative comparison of the different light

The paper presents CCD photometry for stars in three fields centered on the old open cluster NGC 188 and in four fields on the intermediate-age cluster NGC 7789, which has been performed with the aim of investigating the HR diagram distribution of the cluster's Main-Sequence (MS) stars. A sufficiently well-defined sequence of subgiant, turn-off

The magnetic field of the Ap star Epsilon UMa was measured using the Zeeman-Doppler Imaging method. Ultrahigh S/N polarized profiles of the 4923 A magnetically sensitive Fe II line were recorded. Unambiguous Zeeman signatures were found at phases here S/N was greater than or equal to 1750.

From a new infrared photometry of the globular cluster M10 its interstellar extinction and distance i~odu1us are discussed. This is done by comparison with the well-studied clusters M3, M13, and M92. Final values of E(B - V) = 0.17 ± 0.05 and (M~ - V) = 14.0 ± 0.3 are proposed. The dependence on metallicity of these values is briefly discussed

The first results of a study of F-type MS stars using the He I D3 absorption feature at 5876 A as an indicator of stellar activity and structure are presented. The observations were obtained with the QUB echelle spectrograph at the Cassegrain focus of the 4.2 m William Herschel telescope. Seventeen F-stars of the Hyades main sequency were chosen as