Exploring the surface properties of transneptunian objects and Centaurs with polarimetric FORS1/VLT observations

摘要

Context. Polarization is a powerful remote-sensing method to investigate solar system bodies. It is an especially sensitive diagnostic tool to reveal physical properties of the bodies whose observational characteristics are governed by small scatterers ( dust, regolith surfaces). For these objects, at small phase angles, a negative polarization is observed, i.e., the electric vector E oscillates predominantly in the scattering plane, contrary to what is typical for rather smooth homogeneous surfaces. The behavior of negative polarization with phase angle depends on the size, composition and packing of the scatterers. These characteristics can be unveiled by modelling the light scattering by the dust or regolith in terms of the coherent backscattering mechanism.