Subaru Lightcurve Observations of Sub-km-sized Main-belt Asteroids

Abstract

Investigations of the spin period and shape distributions for a certain asteroid group using their lightcurve observations are essential to understand collisional evolution of that group. We therefore conducted lightcurve observations of such asteroids with the Subaru telescope + Suprime-Cam, which can detect many asteroids in a single field of view at the same time. And from them we selected main belt asteroid (MBAs) and determined their spin periods and shapes. Although about 4000 asteroids are currently listed in the spin period catalogue, it includes a very small number of subkm-sized MBAs which are considered to be outcomes from the collisional evolution in the main asteroid belt. Meanwhile, most asteroids detected by our Subaru observation are in the size range between 0.1–1 km i