Digging for Cosmic Gold: Unveiling the Secrets of a Rare r-Process Star in the Ultraviolet
Hansen et al. analyze the metal-poor star J0538, revealing detailed abundances of 43 elements, including rare r-process products like gold and cadmium. Using UV observations from Hubble, they find unexpected star-to-star variation, suggesting non-LTE effects. Their findings support ongoing efforts to trace the cosmic origins of heavy elements and hint at the star’s possible origin in a disrupted dwarf galaxy.
Unearthing Ancient Stars: The Discovery of Two Metal-Poor R-Process Enriched Stars
Astronomers discovered two ancient metal-poor stars enriched in r-process elements, shedding light on the origins of heavy elements. BPS CS 29529-0089, an r-II star, likely formed in the Milky Way’s proto-disk, while TYC 9219-2422-1, an r-I star, originated in the Gaia-Sausage-Enceladus merger. Their chemical signatures suggest enrichment by neutron star mergers and possibly a single Population III supernova, challenging existing theories on galactic evolution.
Exploring the Chemical Fingerprints of Metal-Poor Stars: Insights from the MINCE III Project
The MINCE III project analyzes 99 intermediate-metallicity stars to understand neutron-capture elements, key to the Milky Way’s chemical history. Using high-resolution spectra, the study reveals chemical abundances, including unique findings like a lithium-rich star. Results align with models of Galactic evolution, highlighting the origins of heavy elements through processes like supernovae and neutron-star mergers, advancing our understanding of the Galaxy's formation.
The Riddle of Cosmic Heavyweights: How Stars Forge Elements in the Early Universe
The CERES project investigates how early stars formed heavy elements through neutron-capture processes. Focusing on 52 ancient metal-poor stars, the study found that the rapid r-process dominated at low metallicities, while the slower s-process emerged later. Variations in element abundances suggest diverse nucleosynthesis events, with findings aligning well with galactic chemical evolution models, shedding light on the universe's early chemical enrichment.