The Department of Astronomy 2025-2026 Colloquium Series Presents:

Title: Searching for the First Stars with Stellar Archaeology

Abstract: The first stars formed directly out of pristine big bang material. These metal-free Population III stars are thought to have been unusually massive, and their lives and deaths set the stage for all subsequent cosmic evolution. The properties of Population III stars cannot be directly determined at high redshift, but they still can be accessed observationally using nearby relic stars and galaxies that have survived from ancient times with an approach called Stellar Archaeology. The elemental abundances of such old, metal-poor stars encode otherwise inaccessible information about the first stars. I will present recent insights into the nature of the first stars gleaned from stellar archaeology, including new observational constraints on the nature of the first supernova explosions and steps towards understanding the initial mass function. I will show that current methods are likely probing only a subset of all Population III stars that existed. These limitations can likely be overcome as we move into the era of industrial stellar spectroscopy and extremely large telescopes.