NEW FEATURES IN THE EV LACERTAE FLARES DISCOVERED BY FAST HIGH-PRECISION UBVRI PHOTOMETRY

The flares fine structure lies often below the detection limit for pho tometry data. UBVRI high-speed observations combined with synchronous monitoring at two telescopes situated far from each other allowed us t o detect new small-amplitude features in the flare activity of EV Lac, Digital filtering of the light curves with a Gaussian window was used . We found that some flare events are composed of a flare and an inten sity drop having a crater-shaped structure centered at the flare peak. Fading amplitudes extend from 0.1 to 0.01 mag.