STROMGREN PHOTOMETRY OF 3 DOUBLE MODE HIGH AMPLITUDE DELTA-SCUTI STARS

uvby-beta photoelectric photometric observations of the three double m ode high amplitude delta-Scuti stars AE UMa, RV Ari and BP Peg are pre sented. Periodogram analyses are performed using the Fourier Transform Method. It is found that in all three stars the power spectra are com plex and a large number of frequencies has been identified. For each s tar, all these frequencies are shown to be harmonics or combinations o f two main frequencies nu-1 and nu-2 corresponding to the fundamental and first radial pulsation modes, respectively. Intrinsic b - y, m1 an d c1 values are derived and the physical parameters of these stars are determined.