2024/01/04 by Alexander P. Ji, Sanjana Curtis, Ji, Alexander P. +92 · 1 voice · 5 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Big Bang nucleosynthesis #Galaxy #Low Mass #Metallicity #Milky Way #Nucleosynthesis #Physics #Redshift #Reionization #Stars #Stellar nucleosynthesis #Stellar, planetary, and galactic studies #astro-ph.GA #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.2401.02484
published in arXiv (Cornell University) (Cornell University)
openalex publication_date 2024/01/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Stars formed with initial mass over 50 Msun are very rare today, but they are thought to be more common in the early universe. The fates of those early, metal-poor, massive stars are highly uncertain. Most are expected to directly collapse to black holes, while some may explode as a result of rotationally powered engines or the pair-creation instability. We present the chemical abundances of J0931+0038, a nearby low-mass star identified in early followup of SDSS-V Milky Way Mapper, which preserves the signature of unusual nucleosynthesis from a massive star in the early universe. J0931+0038 has relatively high metallicity ([Fe/H] = -1.76 +/- 0.13) but an extreme odd-even abundance pattern, with some of the lowest known abundance ratios of [N/Fe], [Na/Fe], [K/Fe], [Sc/Fe], and [Ba/Fe]. The implication is that a majority of its metals originated in a single extremely metal-poor nucleosynthetic source. An extensive search through nucleosynthesis predictions finds a clear preference for progenitors with initial mass > 50 Msun, making J0931+0038 one of the first observational constraints on nucleosynthesis in this mass range. However the full abundance pattern is not matched by any models in the literature. J0931+0038 thus presents a challenge for the next generation of nucleosynthesis models and motivates study of high-mass progenitor stars impacted by convection, rotation, jets, and/or binary companions. Though rare, more examples of unusual early nucleosynthesis in metal-poor stars should be found in upcoming large spectroscopic surveys.