Zhilyaev B. Rapid small-scale variability of stars.

A range of problems related to the study of small-scale rapid variability of the celestial bodies are considered. A number of fast light variations of stars, gamma-ray bursts, and short bursts in galactic nuclei are investigated. The methods for estimating the parameters of harmonics, stochastic variability, and analysis of data obtained at random moments of time are developed. The Synchronous Network of distant Telescopes is established. We have detected oscillations in stellar flares, in the giant V390 Aur, flashes in galaxies NGC 7331 and NGC 1068 with duration of about 1 s, short-term fluctuations in the cosmic gamma-ray bursts. A series of observations to determine the accuracy of ground-based photometry were carried out. We made numerical simulation to determine the limits for ultrahigh frequency photometry. It is shown that photometry of sparse quantum fluxes in the absence of the light curves associated with the weakness of the observed object or finding ultrahigh frequency photometry impossible in the time representation can be successfully carried out in the frequency Fourier representation.