Fast rotations of near-Earth asteroids revealed by video observations

Tomo-e Gozen carried out video observations of 60 tiny (diameter less than 100 m) near-Earth asteroids (NEAs) and successfully derived rotational periods and axial ratios of 32 NEAs. The distribution of the tiny NEAs in a diameter and rotational period (D-P) diagram is truncated around a period of 10 s. The dependence of the tangential YORP effect on the rotational period potentially explains the observed pattern in the D-P diagram.