The size distribution of main-belt asteroids from IRAS data

The IRAS data base on asteroid albedos and diameters has been used to derive size distributions for a set of about 4000 numbered main-belt asteroids and for various subsets defined according to the semimajor axis range and family memberships. Different procedures have been used to obtain albedo estimates for the (mostly small) members of the sample not observed by IRAS, allowing us to assess the sensitivity of the derived size distributions to the assumptions used for this purpose.