Spectacular Nucleosynthesis from Early Massive Stars

Ji, Alexander P., Curtis, Sanjana, Storm, Nicholas, Chandra, Vedant, C. Schlaufman, Kevin, G. Stassun, Keivan, Heger, Alexander, Pignatari, Marco, Price-Whelan, Adrian M. et al (2024) Spectacular Nucleosynthesis from Early Massive Stars. Astrophysical Journal Letters, 961 (2). ISSN 2041-8205

[thumbnail of VOR]
PDF (VOR) - Published Version
Available under License Creative Commons Attribution.


Official URL: https://doi.org/10.3847/2041-8213/ad19c4


Stars that formed with an initial mass of over 50 M ⊙ 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 follow-up of the SDSS-V Milky Way Mapper, which preserves the signature of unusual nucleosynthesis from a massive star in the early Universe. J0931+0038 has a 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 M ⊙, 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 the 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.

Repository Staff Only: item control page