  We have analyzed Beta Pictoris photometric measurements obtained from La
Silla by the Geneva Observatory from 1975 to 1992. These data show evidence of
variations in the brightness of the star, with no color dependency. Here, we
demonstrate that the light variations are present on long as well as on short
time scales. On a long time scale, we show that the apparent magnitude of Beta
Pic decreased by 0.011 +/- 0.004 mag from 1979 to 1982. Moreover, when we
consider all the measurements, the chance that there is no variation at all can
be estimated to be less than 10E-4. On short time scales there is a peculiar
feature observed during about 30 days; the variations may be as high as 0.04
magnitude. A maximum entropy reconstruction of the photometric data is
tentatively proposed and some physical interpretations are presented.
