Polluted Stars as Tracers of Binarity and Nucleosynthesis

Explore a 20-minute astronomy lecture examining polluted binary star systems and their role in understanding stellar evolution and nucleosynthesis. Delve into groundbreaking research combining long-term radial-velocity monitoring, high-resolution spectroscopy, and Gaia distance measurements to study binary systems where one star has accreted material from an AGB (Asymptotic Giant Branch) companion that has since become a white dwarf. Learn how incorporating Hipparcos and Gaia astrometric data has enabled the first-ever mass determinations of these faint white dwarf companions, providing direct insights into their AGB progenitors. Examine the challenges in current binary evolution and nucleosynthesis models, which fail to fully explain the orbital and chemical properties of these polluted star systems, highlighting important gaps in our understanding of AGB stars, their outflows, and binary star interactions.