Influence of the YORP Effect on the Rotation of Small Main-Belt Asteroids

Abstract

The distribution of rotation rates of small (D = 3–15 km) main-belt asteroids is analyzed in the context of the probable influence of solar radiation on the rotation of asteroids (YORP effect). It is demonstrated that the evolution of this distribution with heliocentric distance (i.e., the presence of well-marked slow and fast rotation excesses in the inner part of the belt, which become less noticeable in the middle part and are almost indistinguishable in the outer part) is well accounted for by the YORP effect. The influence of this effect on the studied asteroid population is rather weak compared to its influence on near-Earth asteroids, which are 3–4 times smaller on average and with ~3 times more intense solar irradiation; however, it is still sufficiently significant to be identified reliably in the available observational data.