UBV AND UVBY PHOTOMETRY OF THE MAGNETIC CP STAR-56 ARIETIS - 1990 AND 1991

UBV and uvby photometry of the magnetic CP Star 56 Arietis from the Braeside Observatory and the Four College Automated Photoelectric Telescope, respectively, significantly differs from previously published values. Observations with each filter taken in the fall of 1990 show small differences in the shapes of the light curves compared with similar observations a year later. A possible explanation consistent with the radiative diffusion model for such stars is that we are observing a free body precession of a spotted star. As there is now clear evidence that the light curves of at least one CP star do change, it is desirable to continue these observations to see if these changes are periodic albeit that the period may be of order of a decade for 56 Ari.