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The photometric properties of the late-type star PZ Mon are analysed assuming the presence of spots on its surface. The long-term variability in brightness is considered using photographic data together with photoelectric data in the B band. The combined light curve covers the time span from 1898 to 2004 and shows two deep minima which might be interpreted as an activity cycle with a period of 50 years. The investigation of seasonal variations is based on UBVRI observations carried out with the 1.25 m telescope at the Crimean Astrophysical Observatory in 1992–2004. The derived colours of PZ Mon indicate that the spectral type of the star is K5 and therefore the parameters of spots were calculated adopting a value for the temperature of the photosphere of 4800 K. Applying the simple model of star spots we found that a seasonal variability can be produced by spots which cover 17–30% of the hemisphere. The spot temperatures are constant and close to 2700 K. If the deep minima on the long-term curve are also ...

A quick digital method based on the PARSEC measuring complex which was developed in the Main Astronomical Observatory (Ukraine) is proposed to search for long-term variability in the brightness of red dwarfs. The capability of this scanning complex was tested earlier when it was used to digitize photographic plates successfully in the process of creating the astrometric catalogue. Application of this complex and special software to compute digitized images and to obtain photometrical data is discussed briefly.