On the Maximal Size of Chondrules in Shock Wave Heating Model

Abstract

The shock wave heating model is one of the possible mechanisms that could form chondrules. Recently, it is suggested that the shock wave heating model can explain some chondrule features including the maximum temperature and cooling rates. Here we show that another two chondrule features, characteristic size and rotation rates, can be explained naturally, in the framework of the shock wave heating model. The sizes of chondrules are bounded by the balance between the surface tension and the ram pressure on a molten droplet. The acceptable upper bound is acrit ≃ 1 mm. Moreover, when a chondrule forms through the disruption of a larger droplet, it acquires a spin of the order of ω ≃ 1 × 103 rad s-1. Both features are consistent with observations.