|
An investigation into the origin of group 4
stardust grains.
Bose M., Stadermann F. J., and Floss C. (2008)
Lunar & Planet. Sci. 39, Abstract #1099.
ABSTRACT
Silicate and oxide stardust grains characterized by
18O enrichments are referred to as group 4
grains. Low mass/high metallicity red giant or asymptotic
giant branch stars and Type II supernovae are possible
sources for group 4 grains. The small size of silicate and
oxide presolar grains often hinders their study using
multiple isotope systems. There is also a lack of elemental
information for most of these grains. The present work aims
to acquire additional isotopic (e.g., Si) and elemental data
on group 4 grains. We then try to reproduce the O isotopes
of group 4 grains by mixing material from five layers of the
SN ejecta and test if the mixing ratios predict the measured
Si isotopic compositions. The Si isotopes are chosen in our
study since large numbers of presolar silicates have been
discovered in extraterrestrial materials.
|