Catherine Manea (University of Utah)

Stars act as chemical fossils, preserving the composition of their birth environments while recording the chemical evolution of their galaxy. Yet, the precision of current spectroscopic survey abundances is insufficient for fully disentangling the processes that govern Galactic chemical evolution, constraining the origins of the elements, and probing the formation pathways of substellar companions. I will present several projects that leverage high precision stellar abundances to address these challenges. First, I will introduce a new differential abundance catalog of ~1500 Solar-neighborhood FGK dwarfs that achieves precisions of 0.005-0.05 dex, making it among the largest datasets of its kind. This sample enables stringent constraints on the chemical homogeneity of the Solar neighborhood and the evolution of age-abundance trends across metallicity for more than 30 elements. Second, I will discuss recent works that identify and study a population of stars with extreme (~10x solar) neutron-capture element abundances to probe binary mass transfer and internal stellar evolution. I will also discuss a newly identified class of Solar metallicity stars that show enhancements in both slow and rapid neutron-capture process elements and may provide some of the strongest observational evidence to date for intermediate neutron-capture nucleosynthesis at Solar metallicities. Finally, I will highlight recent works that use high precision abundances of stars to characterize the substellar companions that they host. Together, these results illustrate how extremely precise stellar abundances enable a detailed, unified view of Galactic chemical evolution, nucleosynthesis, and substellar object formation.