Element abundance patterns in stars indicate fission of nuclei heavier than uranium
Abstract
The heaviest chemical elements are naturally produced by the rapid neutron-capture process (r-process) during neutron star mergers or supernovae. The r-process production of elements heavier than uranium (transuranic nuclei) is poorly understood and inaccessible to experiments, so must be extrapolated using nucleosynthesis models. We examine element abundances in a sample of stars that are enhanced in r-process elements. The abundances of elements Ru, Rh, Pd, and Ag (atomic numbers Z = 44 to 47, mass numbers A = 99 to 110) correlate with those of heavier elements (63 <= Z <= 78, A > 150). There is no correlation for neighboring elements (34 <= Z <= 42 and 48 <= Z <= 62). We interpret this as evidence that fission fragments of transuranic nuclei contribute to the abundances. Our results indicate that neutron-rich nuclei with mass numbers >260 are produced in r-process events.
Keywords
Cite
@article{arxiv.2312.06844,
title = {Element abundance patterns in stars indicate fission of nuclei heavier than uranium},
author = {Ian U. Roederer and Nicole Vassh and Erika M. Holmbeck and Matthew R. Mumpower and Rebecca Surman and John J. Cowan and Timothy C. Beers and Rana Ezzeddine and Anna Frebel and Terese T. Hansen and Vinicius M. Placco and Charli M. Sakari},
journal= {arXiv preprint arXiv:2312.06844},
year = {2023}
}
Comments
Authors' version of manuscript published in Science on December 07, 2023