2007PASP..119..733A

We studied differential single-channel Strömgren uvby observations of four magnetic CP (mCP) stars, obtained with the Four College Automated Photoelectric Telescope (FCAPT), which now have two epochs of observations. To bring the recent photometry of BN Cam into agreement with earlier FCAPT photometry, we adjusted its period to 2.73501 days. As we found several older photometric studies whose data are consistent with this value, its period appears to have been constant for the past 35 years. We refined the period of EP Vir to 16.3071 days and reduced the errors in its ephemeris. When we compare the light curves from the observing seasons in which complete light curves were obtained, we find the small differences among them to be suggestive of variability. For FF Vir and HD 184905, the periods are 129.99 and 1.84535 days, respectively, as found by previous FCAPT data studies. Their light curves are similar to those of previous uvby and V measurements for the past 35 years.