<sup>60</sup>Fe and<sup>244</sup>Pu deposited on Earth constrain the r-process yields of recent nearby supernovae
A. Wallner, M.B. Froehlich, M.A.C. Hotchkis, Norikazu Kinoshita, M. Paul, Martin Martschini, Stefan Pavetich, S.G. Tims, N. Kivel, D. Schumann, Maki Honda, Hideaki Matsuzaki, Takeyasu Yamagata
Abstract
Natural plutonium from supernovae The rapid neutron capture process (r-process) produces many of the heavy chemical elements, but the astrophysical settings where it occurs remain unclear. Leading candidates are neutron star mergers and some types of supernovae. Wallner et al. analyzed the plutonium content of a deep-sea crust sample, identifying a few dozen atoms of the r-process isotope plutonium- 244 that were delivered to Earth within the past few million years. There was a simultaneous signal of iron-60, which is known to be produced in supernovae. Comparing the ratios of these isotopes constrains the relative contributions of supernovae and neutron star mergers to r-process nucleosynthesis. Science , this issue p. 742