On presolar meteoritic sulphides

Abstract

DISCOVERIES of isotopic anomalies in meteorites^1–4 inspired those same research groups to postulate nucleosynthetic inhomogeneities that were somehow carried into the early Solar System. Clayton^5,6 developed a picture treating most anomalies as extinct radioactivities trapped in mineral condensations in the expanding sites of explosive nucleosynthesis, presumably supernovae or novae⁷. As evidence for supernovae condensation grows, it becomes clear that one wants not only isotopic but also mineralogical evidence of presolar grains. What supernovae condensates bearing unique signature are likely to survive? We advance arguments here that one should search among the ubiquitous sulphides present in meteorites, searching especially for sulphides of titanium. Our reasoning is that many sulphides, especially of titanium, will not be expected in solar condensation sequences but are expected to dominate certain key zones of supernovae expansion.