UBV photometry of the Seyfert galaxy Akn 120 in 1974-1999

Photoelectric UBV observations of the Akn 120 nucleus in 1974-1999 are pres ented. Based on multiaperture photometry, we determine the disk parameters for Akn 120, which turn out to be typical of spiral galaxies. We use our ob servations together with published data to construct the UBV light curves o ver a period of 25 years. The color indices of the variable source are dete rmined. At the average (over the period of observations) B-V = 0.13 +/- 0.0 3 and U-B = -1.02 +/- 0.04 for the variable component, its U-B color exhibi ted appreciable variations during two significant fadings: -1.25 +/- 0.03 i n 1974-1977 and -0.68 +/- 0.03 in 1990-1994. We assume that these variation s may be caused by a change in the degree of gas opacity beyond the Balmer continuum and/or in the gas temperature at a mean T-e approximate to 15000 K.