New variable chemically peculiar stars identified in the Hipparcos archive

Since variability of chemically peculiar (CP) stars plays an important role for the astrophysical explanation of their outstanding behaviour, we have identified new variable CP stars listed in Renson's catalogue using the extensive Hipparcos Variability Annex. From the 293 objects found, 33 were excluded because they are no CP stars and/or have no period listed, half of the remaining stars are newly identified and half had been already included in the catalogue of variable CP stars by Catalano & Renson (1997). Most of the newly identified variability is due to an apparent magnetic field coupled with stellar rotation (oblique rotator model). The constraints of this model are fulfilled for all but three CP2 stars. Variations of bona fide Am-Fm stars are exclusively explained by eclipses of binary systems. Furthermore eight candidates of the gamma Doradus group (pulsating Am-Fm stars) were detected.