Research Repository

# 129I and 247Cm in meteorites constrain the last astrophysical source of solar r-process elements

## Authors

Benoit Côté

Marius Eichler

Andrés Yagüe

Nicole Vassh

Matthew R. Mumpower

Blanka Világos

Benjámin Soós

Almudena Arcones

Trevor M. Sprouse

Rebecca Surman

Marco Pignatari

Mária K. Pet?

Benjamin Wehmeyer

Thomas Rauscher

Maria Lugaro

### Abstract

Meteoritic analysis demonstrates that radioactive nuclei heavier than iron were present in the early Solar System. Among them, $^{129}$I and $^{247}$Cm both have a rapid neutron-capture process ($r$ process) origin and decay on the same timescale ($\simeq$ 15.6 Myr). We show that the $^{129}$I/$^{247}$Cm abundance ratio in the early Solar System (438$\pm$184) is immune to galactic evolution uncertainties and represents the first direct observational constraint for the properties of the last $r$-process event that polluted the pre-solar nebula. We investigate the physical conditions of this event using nucleosynthesis calculations and demonstrate that moderately neutron-rich ejecta can produce the observed ratio. We conclude that a dominant contribution by exceedingly neutron-rich ejecta is highly disfavoured.

### Citation

Côté, B., Eichler, M., Yagüe, A., Vassh, N., R. Mumpower, M., Világos, B., …Lugaro, M. (2021). 129I and 247Cm in meteorites constrain the last astrophysical source of solar r-process elements. Science, 371(6532), 945-948. https://doi.org/10.1126/science.aba1111

Journal Article Type Article Jan 25, 2021 Feb 26, 2021 Feb 26, 2021 Dec 17, 2020 Mar 22, 2021 Science 0036-8075 American Association for the Advancement of Science Peer Reviewed 371 6532 945-948 https://doi.org/10.1126/science.aba1111 Solar and Stellar Astrophysics; High Energy Astrophysical Phenomena; Nuclear Theory https://hull-repository.worktribe.com/output/3523740

Article (1.2 Mb)
PDF