SIMULTANEOUS UVBY-BETA-PHOTOMETRY OF GP ANDROMEDAE

Simultaneous uvbybeta photometric observations of the high amplitude delta Sct type star GP And are presented. Ten new times of light maxima have been obtained. Using the classical O-C method, it is found that the pulsation of this star can be well described by means of a quadratic ephemeris with the period increasing at a rate of dP/Pdt = 13.0(+/- 2.8) 10(-8) y-1 over the last nineteen years. Intrinsic b - y, m1 and c1 values are derived and the physical parameters of this star are determined.