Rosenbush V. The scattered light properties of small Solar System bodies

The thesis is devoted to investigation of the three families of small Solar System bodies, namely comets, asteroids, and planetary satellites, which in spite of different physical nature display many common properties in the scattered light. The results of the thesis are based on the observational polarimetric and photometric data of 21 comets, 10 planetary satellites, and 6 asteroids collected by author in 1988-2006 at different telescopes equipped by imaging and aperture photopolarimeters. The results of comprehensive investigations of the opposition effects are given. The polarization opposition effects in several high-albedo objects are discovered. On the basis of polarimetric and photometric data at small phase angles a class of high-albedo Solar System bodies, including E-type asteroids 44 Nysa and 64 Angelina, the planetary satellites Io, Europa, Ganymede, and Iapetus, the A and B rings of Saturn, with unique opposition properties is revealed and thereby it is evidenced that the renowned effectof coherent backscattering is an effective physical mechanism of light scattering in natural medium of the Solar System. The separation of the phase-angle and longitude curves of polarization was made for Callisto and Iapetus. Non-zero polarization of Io, Europa, and Ganymede at the inversion point is revealed. Such residual polarization may be produced by inhomogeneities and/or optical anisotropy of the satellite surfaces. A new classification of comets is suggested on the base of the scattered light and thermal emission properties of cometary dust. The peculiarities in polarized light of comets were found. Among them are circular polarization, anomalous spectral dependence of linear polarization, alignment of dust particles in the cometary atmospheres, variations of polarization parameters during the non-steady-state processes in comets. New regularities and effects in the scattered light of selected asteroids and planetary satellites were found.