The Origin of Presolar Silica Grains in AGB Stars
Abstract
We have found two presolar silica grains in ALH A77307, which exhibit excesses in 17O but are normal in 18O. Silicon-oxide grains probably form during rapid cooling under non-equilibrium conditions in O-rich AGB stars with low Mg/Si ratios.
Citation
41st Lunar and Planetary Science Conference, held March 1-5, 2010 in The Woodlands, Texas. LPI Contribution No. 1533, p.1812