2025/12/10 by Kaitlin Webber, Terese T. Hansen, Webber, Kaitlin B. +43
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Gamma-ray bursts and supernovae #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2512.10003
openalex publication_date 2025/12/10 · openalex created_date 2025/12/13 · openalex updated_date 2026/07/28
We present a detailed chemical abundance analysis of the three brightest known stars from each of the Turranburra and Willka Yaku stellar streams using high-resolution Magellan/MIKE spectra. Abundances for 27 elements, ranging from carbon to dysprosium, were derived. Our results support the original classification that Turranburra, with a low average metallicity of [Fe/H]=-2.45 ± 0.07, likely originates from a dwarf-galaxy progenitor. Willka Yaku has a low average metallicity of [Fe/H]=-2.35 ± 0.03 with a small scatter in the abundances, consistent with a globular cluster progenitor as suggested by previous studies. Both streams exhibit mild enhancements in neutron-capture elements, with averages of [Eu II/Fe]= 0.47 ±0.09 for Turranburra and 0.44 ±0.05 for Willka Yaku, consistent with enrichment from an r-process event. A similar enrichment is observed in other stellar streams, and we further discuss this signature as it relates to the potential enrichment histories of these two streams.