Polarimetric observations of small asteroids: Preliminary results

A campaign of polarimetric observations of small (D < 50 km) asteroids obse rved by the IRAS satellite is presently under way in order to obtain indepe ndent albedo estimates of these objects. For this purpose, the known relati onships between the albedo and the parameters (slope h, P-min) describing t he phase-polarization curve are used. The main goal of this research is to obtain an independent check on the size dependence of the asteroid albedo d istribution exhibited by the IRAS data. At the same time, we can look for t he presence of possible systematic effects influencing the radiometric albe do estimates for objects close to the IRAS detection limit. Although some i ndication that IRAS-derived albedos tend to be on the average slightly high er than polarimetric albedos, preliminary results are not sufficient to dra w definitive conclusions. An evident discrepancy has been found only for th e A-class asteroid 863 Benkoela, (C) 1999 Academic Press.