Re: Delta Cep period analysis of visual observations > Determining epochs by fitting visual measures to master light curves and > then plotting on O-C diagrams shows just the lack of time resolution that > you would expect. Visual measures with an accuracy of +/- 0.3 magnitudes > produce epochs about 20-50 times less accurate than pep measures which are > based on measures with accuracies of +/- 0.005 magnitudes. I have just placed GIF figures, PDM theta plot and phase-averaged light curve (P=5.3660 d is used). The phase bin in the latter figure is 0.02. The figures look (at least) as pretty as our usual superhump analysis :-) I have not yet done cross-correlation, but as inferred from the sharpness of the ascending branch, the error in O-C would not exceed phase 0.02. http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/Cep/Delta_Cep/dceppdm.gif http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/Cep/Delta_Cep/dcepph.gif Regards, Taichi Kato