Synchronous Three Colour Stellar Photometry at the Catania Astrophysical Observatory

A synchronous three colour stellar photometer using a single photomultiplier has been constructed at Catania. In this communication the characteristics and the efficiency of this photometer are briefly described. At present the instrument is used for simultaneous UBV photometry of flare stars. A graph of simultaneous measurements in the UBV system of a flare of EV Lac is shown. A more detailed description of the instrument had been published elsewhere (Cristaldi. Paterno 1968).