The long-term behaviour of the photometric variability of β Cassiopeiae.

1003 V measurements of β Cas divided into three observing seasons are discussed. Their analysis performed with both the Vanicek least-squares and the classical O-C methods led us to the confirmation of the monoperiodic pulsation. All the photometry available on β Cas (spanning 25 years) was also analyzed; the amplitude of the light curve was found to be constant, while a small period variability can be inferred.