Stellar Genealogy: The Search for the First Stars and Everything in Between

by Dr Vinicius M. Placco (NSF/NOIRLab/US NGO, AZ USA)

Wednesday 15 Apr 2026, 13:30 → 14:30 Europe/Stockholm

FC61 (AlbaNova Main Building)

The lowest metallicity stars in the Milky Way Halo are the fossil records of the earliest star-forming environments in the Universe. Chemo-dynamical studies of such rare objects can address a myriad of open questions, ranging from primordial nucleosynthesis and the mass function of the first stars to the nature of the astrophysical r-process and the early merger history of the Milky Way. The detailed abundance patterns of these stellar relics, which can only be obtained from high-resolution spectroscopy, help us build a clear understanding of the pathways that led to the chemical complexity we observe today. In this talk, I will present recent results on the spectroscopic validation of low-metallicity stars selected from narrow-band photometry and low-resolution spectroscopy. I will also talk about the discovery of chemically peculiar stars in the Milky Way, which present chemical abundance patterns that match the ones from the ejecta of a neutron-star merger event and zero-metallicity supernovae. Combined, these efforts are adding key pieces of information to help stellar archaeologists constrain the chemical evolution of the Universe and solve the intricate chemo-dynamical puzzle of the formation of the Milky Way.