Statistical evidence for fast and slow asteroid rotations using Bayesian methods

Asteroid rotation rates have been analysed by many authors in the past. The statistical results and physical interpretations of the models have varied widely. Bayesian statistics are used here to analyse the rotation rates of 749 asteroids. The larger asteroids are best fitted with a single Maxwellian distribution while the smaller asteroids are fitted by a mixture of Maxwellian distributions. The optimal separation point, determined by the data fit, occurred around 33 km. The smaller asteroids are composed of a mixture of four Maxwellians corresponding to populations of slow rotators, fast rotators and a population identical to the larger asteroids.