Discovery of ancient silicate stardust in a meteorite.
We have discovered nine presolar silicate grains from the carbonaceous chondrite Acfer 094. Their anomalous oxygen isotopic compositions indicate formation in the atmospheres of evolved stars. Two grains are identified as pyroxene, two as olivine, one as a glass with embedded metal and sulfides (GEMS), and one as an Al-rich silicate. One grain is enriched in 26Mg, which is attributed to the radioactive decay of 26Al and provides information about mixing processes in the parent star. This discovery opens new means for studying stellar processes and conditions in various solar system environments.
Laboratory for Space Sciences and the Physics Department, Washington University, St. Louis, MO 63130, USA. nguyen@wustl.edu
Ann N
AN
Nguyen
Ernst
E
Zinner
D000535:Aluminum / Q000032:analysis; D019443:Cosmic Dust; D058085:Iron Compounds / Q000032:analysis; D007554:Isotopes; D008274:Magnesium / Q000032:analysis; D017616:Magnesium Compounds / Q000032:analysis; D019110:Meteoroids; D008903:Minerals / Q000032:analysis; D010103:Oxygen Isotopes; D017640:Silicates / Q000032:analysis* / Q000737:chemistry
D019443:Cosmic Dust; D058085:Iron Compounds; D007554:Isotopes; D017616:Magnesium Compounds; D008903:Minerals; D010103:Oxygen Isotopes; D017640:Silicates; C092478:pyroxene; C034475:olivine; D000535:Aluminum; D008274:Magnesium