AN ORBITAL PERIOD STUDY OF SZ PISCIUM

The variations of the orbital period of the RS CVn-type binary system SZ Psc are examined through a detailed description of the O-C diagram and the use of a new analysis technique. Continuous changes of very la rge magnitude have been found. They are considered as short-timescale variations whose character is investigated for periodicity or as short -timescale variation of periodic or non-periodic behaviour eventually carried by an underlying long-timescale variation. The prospective phy sical mechanisms that could have modulated the orbital period in the o bserved way, have been examined for both cases. A combination of a mag netic activity cycle mechanism and an enhanced stellar wind are found to reproduce satisfactorily the period changes.