SEMIREGULAR VARIABLES OF TYPES SRA AND SRB - VARIABILITY CLASSIFICATION IN THE GCVS

We studied the shape and the quality of light curves of oxygen-rich Se miregular Variables and the occurrence of multiple and variable period s among this group of variables to investigate whether there is any co rrelation between the subgroups of SRVs described by Kerschbaum and Hr on (1992) and these parameters. For this purpose we used the data and the light curve references given in the General Catalogue of Variable Stars (4th edition, GCVS4). To judge the quality of the light curves w e introduced a new quality classification based on the number of obser ved cycles and the mean number of observations per cycle. We also comp ared our system with a system based on the subjective impression of th e light curve similar to the one used in the GCVS4. It was found that for more than 40% of the objects investigated, the data given in the G CVS4 seem to be based on badly known and insufficient light curves. No correlation between the shape of the light curves and the classificat ion of Kerschbaum and Hron could be found. More objects with multiple or variable periods were found among the objects with very long period s than among the objects with short periods.