Fig. 2
From: Asteroid spin-rate studies using large sky-field surveys
This figure is reproduced from Chang et al. (2015, 2016)
Diameter vs. semi-major axis of the PTF-U2s. Most of the PTF-U2s are main-belt asteroids. Because of the limiting magnitude (i.e., \({\sim} 14\) to \({\sim} 21\) mag), the diameter range changes with semi-major axis. The albedo values adopted in the diameter calculations are indicated in the plot.