Photometrically simply behaving mCP stars

We analyzed uvby and Hp light curves of 19 well observed magnetic CP stars selected from the "On-line database of photometric observations of mCP stars" of which light curves in all the five colours were similar. We assumed that among these photometrically simply behaving (PSB) stars could be found such ones which have a single photometric spot. The insight into such simple situations would help us to comprehend more complicated cases. Light curves of the 19 PSB mCP stars proved to be generally nearly symmetric but surprisingly diverse. The analysis shows that only in the case of HD 110956B, HD 188041, and perhaps HD 193722 we are able to explain their photometric behaviour by a simple one-spot model. Consequently, occurrence of more than one photometric spot on an mCP star is typical.
Comment: 6 pages, 15 figures, The proceedings of the "CP#AP workshop", Vienna 10.-14. Sept. 2007, eds. J. Ziznovsky, J. Zverko, E. Paunzen, M. Netopil, will be published in Contr. Astron. Obs. Skalnate Pleso