PHOTOMETRIC-STUDY OF RS GRU AND RY LEP

Simultaneous uv by beta photometric observations of the high-amplitude delta Set-type stars RS Gru and RY Lep have been collected and new times of light maxima have been obtained. Using the classical O-C method, it is found that the pulsation of RS Gru can be well described by means of a quadratic ephemeris with the period decreasing at a rate of dP/Pdt = -10.6(+/-0.8)10(-8) yr(-1) over more than 30 yr. Intrinsic b-y, m(1) and c(1) values are derived and the physical parameters of these two stars are determined.