Nucleosynthesis origin of PG 1159 stars, Sakurai's object and of rare subclasses of presolar grains

TL;DR

This paper explores the nucleosynthesis processes behind hydrogen-deficient PG 1159 stars, Sakurai's object, and certain presolar grains, linking stellar evolution models with meteorite grain compositions.

Contribution

It provides a theoretical framework connecting late thermal pulse nucleosynthesis to observed stellar and presolar grain compositions.

Findings

AGB models explain He, C, O enhancements in PG 1159 stars and Sakurai's object.

Nucleosynthesis origins of specific presolar grain subclasses are identified.

Low 12C/13C ratios in SiC AB grains are linked to stellar processes.

Abstract

We discuss theoretical AGB predictions for hydrogen-deficient PG 1159 stars and Sakurai's object, which show peculiar enhancements in He, C and O, and how these enhancements may be understood in the framework of a very late thermal pulse nucleosynthetic event. We then discuss the nucleosynthesis origin of rare subclasses of presolar grains extracted from carbonaceous meteorites, the SiC AB grains showing low 12C/13C in the range 2 to 10 and the very few high-density graphite grains with 12C/13C around 10.