Speaker
Description
We investigate the production of the long-lived radioactive isotope K-40
in low-mass asymptotic giant branch (AGB) stars, with a focus on quantifying
the impact of stellar model and nuclear physics uncertainties. Potassium-40 is
a key contributor to radiogenic heating in terrestrial planets,
yet its stellar origin and galactic evolution remain insufficiently well constrained.
Using a set of AGB stellar models spanning a range of masses and metallicities, we examine how variations in convective boundary mixing, mass loss,
and thermal pulse properties influence the synthesis and surface enrichment of
potassium isotopes. In parallel, we assess the sensitivity of K-40 production
to uncertainties in relevant neutron-capture reaction rates along the s-process path,
particularly in the vicinity of argon and potassium isotopes.
Our results will identify the dominant sources of uncertainty affecting K-40 yields
and provide revised estimates of its production in low-mass AGB stars.
We discuss the implications for galactic chemical evolution models and evaluate
the potential contribution of AGB stars to the inventory of radiogenic isotopes
incorporated into exoplanetary systems. These findings will offer new constraints
on the role of stellar nucleosynthesis in setting the internal heat budgets
and long-term geophysical evolution of rocky exoplanets.
| Career stage | Tenured mid-to-late-career researcher |
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