Asteroid Polarimetry: Current Activities and Recent Results
Résumé
Polarimetry is a very useful tool for asteroid studies because it makes it possible to get information on some important physical parameters, like geometric albedo, which are intimately related to surface composition and regolith structure. In recent years there has been a strongly renewed interest in the field of asteroid polarimetry, due to new theoretical and observational results. Some new discoveries have been done, including a few objects exhibiting fairly exotic polarimetric properties, that had not been observed previously. Moreover, it is now largely agreed that polarimetry is the best available technique to derive reliable and fairly accurate estimates of the albedo of small near-Earth objects. On the other hand, some problems are present and deserve a careful attention, including primarily the need of converging towards a unique and improved calibration of the albedo - linear polarization relation. The above subjects are briefly discussed, and some kind of "road map" for further developments is sketched.