Light curve shape variability of SZ cassiopeiae between 1978–1994

The aim of our investigation was toapproach the problem of identification for possiblevariability of light curve shape in case of theclassical Cepheid SZ Cassiopeiae. In order to performsuch a study we analysed eight observational data setsobtained through V photoelectrical photometry,covering a time base of 16 years. We applied theFourier decomposition technique to each data set; theobtained Fourier coefficients were used to calculatethe corresponding amplitude ratios and phasedifferences. Their time behavior were finally studiedin order to search for evidences of the variability ofthe light curve shape.