Toward Complete Isotopic Analysis of Individual Presolar Silicon Carbide Grains: C, N, Si, Sr, Zr, Mo, and Ba in Single Grains of Type X

The isotopic compositions of Sr, Ba, Zr and Mo in single presolar SiC grains from supernovae are different from those expected from either of the dominant heavy element neutron capture nucleosynthesis mechanisms, the s-process and the r-process.