SIMULTANEOUS UVBY PHOTOMETRY OF 28 ANDROMEDAE

Simultaneous uvby photometric observations of the low amplitude delta Scuti type star 28 Andromedae are presented. Analysis of the data usin g the Fourier transform method suggests 28 And as a monoperiodic pulsa tor. Using the classical O-C method, it is found that the pulsation of this star can be well described by means of a linear ephemeris with a period of p=0.d069304118 over the last twenty-four years. Amplitude v ariations are also shown to be present from season to season. The anal ysis of the phase shifts and amplitude ratios between observed light a nd colour variations suggests that 28 And is a non-radial pulsator.