Behavior of grains in early supernova environments

The efficiency of grain destruction by collisional and radiative heating and sputtering in a supernova environment is examined. It is found that radiative heating rapidly destroys any grains composed of magnesium silicates, graphite, silicon carbide, iron, or ices. Quartz grains without impurities could survive evaporation, but sputtering and fragmentation should eliminate all but the smallest grains. It is concluded that grains have no observable effect on early supernovae, but that small surviving particles might serve as condensation nuclei during the later phases of the expansion