In order to study very rapid optical variability of astrophysical objects on time scales between 10−7 s and 102 s (Shvartsman 1977), at SAO the MANIA (Multichannel Analysis of Nanosecond Intensity Alterations) experiment is being used. A special photometric registration system and software has been developed (Beskin et al. 1982’ Plokhotnichenko 1983, Zhuravkov et al. 1994).

One of the applications of these tools is the detection of radiation from accreted or ejected plasma near compact objects. A choice between two models of accretion onto compact objects in binary systems - hydrodynamic flow or magnetc flaring (Shakura & Sunyaev 1973, Pustil’nik & Shvartsman 1974) has not yet been made. Recent optical and X-ray observations of X-ray binaries provide information on their (fast) variability, their nonthermal radio emission, generation of very high energy particles, and nonthermal processes in rapid optical flares (Bartolini et al. 1994, Beskin et al. 1994). However, the data are not fully described by classical hydrodynamical models.