Solar and meteoritic abundance of silicon

Recent lifetime measurements on excited electronic states of neutral silicon lead to a reassessment of widely used experimental transition probabilities of Si I lines. This translates into a 25% downward revision of the Si abundance determined from the solar spectrum. A solar atomic ratio, Si/Ca = 15.5 is inferred. This value coincides with that found in carbonaceous chondrites, but contrasts with ordinary and enstatite chondrites. (author)