| Abstract: The oldest stars in the Milky Way preserve chemical imprints from the early Universe, offering vital clues to element formation processes nearly 13 billion years ago. Using “Stellar Archaeology,” I analyze the chemical properties of these elements to address unresolved questions about their origins, particularly the rapid neutron-capture process (r-process). While neutron star mergers provide evidence of r-process nucleosynthesis, they alone cannot explain its enrichment, and there are still open questions regarding their timescale. In the talk, I will discuss some of the results of r-process stars observed with the Gran Telescopio Canarias (GTC) and the Very Large Telescope (VLT), as well as findings from the HESP-GOMPA survey. I will speak about the newly discovered very metal‑poor (VMP) peculiar stars from the HESP‑GOMPA survey. Additional scientific highlights of the thesis include the first metallicity‑dependent Thorium production ratios, evidence for multiple r‑process sites revealed through differential techniques for the first time, and orbital‑based classification distinguishing RPE stars between the halo and disk of the Milky Way. I will also present insights from data‑driven classification, highlighting diluted RPE stars and potential connections between RPE and CEMP‑r/s stars. |
