CCD observations of Outer-belt asteroids

Abstract

Outer-belt asteroids (Trojan, Hilda and Cybele groups) have been proposed to represent a primordial asteroidal population, with shapesnot significantly altered since the formation of the solar system. To examine this hypothesis, our group is carrying outa program of telescopic CCD observations devoted to the characterization of the rotational properties, composition and shapes of these distant asteroids. The high photometric accuracy of the collected data and the good time sampling allows us to compute reliable amplitudes, rotational periods and Fourier coefficients for most of the the lightcurves. We compare the derived parameters with those of a sample of similarly sized Main-belt asteroids. The results of the analysis and their implications are presented.