60 Fe and 244 Pu deposited on Earth constrain the r-process yields of recent nearby supernovae.

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Bibliographic Details
Title:	60 Fe and 244 Pu deposited on Earth constrain the r-process yields of recent nearby supernovae.
Authors:	Wallner, A., Froehlich, M. B., Hotchkis, M. A. C., Kinoshita, N., Paul, M., Martschini, M., Pavetich, S., Tims, S. G., Kivel, N., Schumann, D., Honda, M., Matsuzaki, H., Yamagata, T.
Source:	Science (pre-March 2025). 5/14/2021, Vol. 371 Issue 6543, p742-745. 4p. 2 Charts, 2 Graphs.
Subjects:	Supernovae, Nuclear astrophysics, Neutron stars, Pulsars, Nucleosynthesis
Abstract:	Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust—iron-60 (60Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (244Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of 60Fe to Earth in the last 10 million years and accompanying lower quantities of 244Pu. The 244Pu/60Fe influx ratios are similar for both events. The 244Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources. [ABSTRACT FROM AUTHOR]
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Database:	Psychology and Behavioral Sciences Collection

Description
Abstract:	Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust—iron-60 (60Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (244Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of 60Fe to Earth in the last 10 million years and accompanying lower quantities of 244Pu. The 244Pu/60Fe influx ratios are similar for both events. The 244Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources. [ABSTRACT FROM AUTHOR]
ISSN:	00368075
DOI:	10.1126/science.aax3972