UVBY PHOTOMETRY OF THE MAGNETIC CHEMICALLY PECULIAR STARS 63-ANDROMEDAE, HD-192913, HR-8240, AND 108-AQUARII

Differential Stromgren uvby photometric observations from the Four Col lege Automated Photoelectric Telescope of four magnetic Chemically Pec uliar stars are presented. We refined the period of 63 And to 4.1890 d ays. The period of the sharp-lined Si star HD 192913 is 16.840 days, a value close to, but slightly different from published values. HR 8240 , a sharp-lined Si star, is found not to be a photometric variable. Co mparison of four color photometry of 108 Aqr by Morrison and Wolff and from the Four College APT indicates that subtle changes in the shapes of the light curves, especially that for u, have occurred suggesting that this star may be precessing.