Stellar Sapphires: The Properties and Origins of Presolar Al_2O_3 in Meteorites

摘要

O-rich circumstellar dust seems to be underrepresented in meteorites, relative to C-rich. Explanations include the possibility that most O-rich stardust grains are silicates and have been destroyed either in the laboratory or in nature and the possibility that presolar Al_2O_3 has a finer grain size distribution than SiC and graphite.