Six years of photometry of HD 185151 = V1764 CYG

In this paper, another five years of photoelectric photometric data on the binary HD 185151 = V1764 Cyg are presented to supplement the 1980 data presented by Bopp et al. (1982). The new data have been examined graphically in two ways. First, it is shown that the light curve, which Bopp et al. (1982) found from their data to be characterized by a neat sinusoidal wave, appears from the following data to have evolved into a more complicated shape. Second, the authors derive, by reading off times of relative maximum and minimum light, an improved value for the photometric period. It is noted that, in terms of the starspot model suggested by Bopp et al. (1982), the rotation of the spotted star in the system would be almost perfectly synchronized with the orbital motion. (Author)