Origins of colors variability among C-cluster main-belt asteroids

The Sloan Digital Sky Survey provides colors for more than 100,000 moving objects, among which a significant fraction has albedos determined. Here we combined and albedo in order to perform cluster analysis on the main-belt asteroid population, identify C-cluster, group of related C-type as defined earlier work. Members this C-cluster are fair agreement with color boundaries B DeMeo Carry (2013). We then compare asteroids those carbonaceous chondrites powders, while taking into account effect phase angle. show that only CM have range asteroids, CO, CR CV being significantly redder. Also, powders average slightly redder C-cluster. members further investigated by looking at variations function diameter. observe visible slope becomes bluer decreasing diameter, transition seems be present around 20 km. discuss origin variation and, if not bias dataset - analysis, conclude it is surface texture smaller objects covered rocks or large fragments, larger particulate surface. blueing interpreted an increased contribution first reflection case rock-dominated surfaces, can scatter light Rayleigh-like manner. do unambiguous evidence space weathering within based however generally nature compared could some extent weathering.