Secular variability of the longitudinal magnetic field of the Ap star Equ

We present an analysis of the secular variability of the longitudinal magnetic field Be in the roAp star γ Equ (HD 201601). Measurements of the stellar magnetic field Be were mostly compiled from the literature, and append also our 33 new Be measurements which were obtained with the 1-m optical telescope of Special Astrophysical Obser- vatory (Russia). All the available data cover the time period of 58 years, and include both phases of the maximum and minimum Be. We determined that the period of the long-term magnetic Be variations equals 91.1±3.6 years, with Be(max) = +577±31 G and Be(min) = 1101± 31 G.