Sliding along the Eddington Limit -- Heavy-Weight Central Stars of Planetary Nebulae

TL;DR

This paper analyzes hydrogen-deficient, hot central stars of planetary nebulae to gain insights into nucleosynthesis and mixing processes during late stellar evolution stages.

Contribution

It provides non-LTE spectral analyses of PG 1159-type stars, offering new observational data on surface compositions related to late stellar evolutionary processes.

Findings

Identification of surface abundances in PG 1159 stars

Insights into nucleosynthesis during late stellar evolution

Spectral analysis of stars in specific planetary nebulae

Abstract

Due to thermal pulses, asymptotic giant branch (AGB) stars experience periods of convective mixing that provide ideal conditions for slow neutron-capture nucleosynthesis. These processes are affected by large uncertainties and are still not fully understood. By the lucky coincidence that about a quarter of all post-AGB stars turn hydrogen-deficient in a final flash of the helium-burning shell, they display nuclear processed material at the surface providing an unique insight to nucleosynthesis and mixing. We present results of non-local thermodynamic equilibrium spectral analyses of the extremely hot, hydrogen-deficient, PG 1159-type central stars of the Skull Nebula NGC 246 and the "Galactic Soccerballs" Abell 43 and NGC 7094.