The Dawes Review 2: Nucleosynthesis and Stellar Yields of Low- and Intermediate-Mass Single Stars

TLDR

The chemical evolution of the Universe is driven by stellar yields, which depend on initial mass, and low‑ and intermediate‑mass stars alter their surface composition through mixing, enriching C, N, F, and s‑process elements, and release these products via winds rather than supernova explosions. This review aims to compile and assess homogeneous stellar yields for single stars below ~10 M⊙ across a range of metallicities, highlighting efforts to address uncertainties. The authors examine single‑star evolution from the main sequence to the AGB, discuss key uncertainties in theoretical models, and compare recent observations that constrain these models. They find that even stars as low as 0.9 M⊙ can contribute to chemical evolution at low metallicity, and provide updated yield tables for low‑ and intermediate‑mass stars.

Abstract

Abstract The chemical evolution of the Universe is governed by the chemical yields from stars, which in turn are determined primarily by the initial stellar mass. Even stars as low as 0.9 M ⊙ can, at low metallicity, contribute to the chemical evolution of elements. Stars less massive than about 10 M ⊙ experience recurrent mixing events that can significantly change the surface composition of the envelope, with observed enrichments in carbon, nitrogen, fluorine, and heavy elements synthesized by the slow neutron capture process (the s -process). Low- and intermediate-mass stars release their nucleosynthesis products through stellar outflows or winds, in contrast to massive stars that explode as core-collapse supernovae. Here we review the stellar evolution and nucleosynthesis for single stars up to ~ 10 M ⊙ from the main sequence through to the tip of the asymptotic giant branch (AGB). We include a discussion of the main uncertainties that affect theoretical calculations and review the latest observational data, which are used to constrain uncertain details of the stellar models. We finish with a review of the stellar yields available for stars less massive than about 10 M ⊙ and discuss efforts by various groups to address these issues and provide homogeneous yields for low- and intermediate-mass stars covering a broad range of metallicities.