Chornyi V. Photometry of small main-belt asteroids. Rotation and binary

This thesis focuses on CCD-photometry of small main-belt asteroids, determination of their axial rotation periods, detection of multiple systems among these objects and the research of their parameters, as well as determination of physical characteristics – absolute brightness, colour indices, diameter and albedo of small asteroids, which were observed using the photometric method for the first time. The main result of this work is the discovery of 15 new binary and 4 triple systems among small main-belt asteroids and determination of their parameters, such as the orbital period and the rotation periods and diameter ratio of their individual components. A fully synchronous binary system of asteroid 8474 Rettig was discovered among the new multiple systems. It represents a rare group of binary asteroids with approximately equally-sized components and synchronous rotation. The parameters of the system have been determined and the diameters of the components have been estimated. Photometric observations of 70 main-belt asteroids with diameters of less than 15 km carried out for the first time, which made it possible to obtain the values of the rotation periods for these asteroids. The analysis of the obtained main parameters of asynchronous multiple systems with a short period of rotation close to the destruction boundary and weak elongation of the primary component has shown that their mean parameters support the theoretical hypotheses of the influence of the YORP effect on the binary formation mechanism. The photometric observations for 25 main-belt asteroids were standardised and for the first time their absolute magnitude and colour index V–R were determined, as well as their diameters, albedo and the mineralogical surface composition were assessed.