Abstract
Among extinct radioactivities present in meteorites, Fe-60 (t(1/2) = 1.49 Myr) plays a key role as a high-resolution chronometer, a heat source in planetesimals, and a fingerprint of the astrophysical setting of solar system formation. A critical issue with 60Fe is that it could have been heterogeneously distributed in the protoplanetary disk, calling into question the efficiency of mixing in the solar nebula or the timing of 60Fe injection relative to planetesimal formation. If this were the case, one would expect meteorites that did not incorporate 60Fe (either because of late injection or incomplete mixing) to show Ni-60 deficits (from lack of 60Fe decay) and collateral effects on other neutron-rich isotopes of Fe and Ni (coproduced with Fe-60 in core-collapse supernovae and AGB stars). Here, we show that measured iron meteorites and chondrites have Fe and Ni isotopic compositions identical to Earth. This demonstrates that 60Fe must have been injected into the protosolar nebula and mixed to less than 10% heterogeneity before formation of planetary bodies.
Original language | English |
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Pages (from-to) | 560-569 |
Number of pages | 10 |
Journal | The Astrophysical Journal |
Volume | 686 |
Issue number | 1 |
DOIs | |
Publication status | Published - 10 Oct 2008 |
Keywords
- methods : analytical
- supernovae : general
- COLLATERAL CONSEQUENCES
- MASSIVE STARS
- nuclear reactions, nucleosynthesis, abundances
- METEORITE PARENT BODIES
- EARLY SOLAR-SYSTEM
- REFERENCE SAMPLE
- ISOTOPIC COMPOSITION
- solar system : formation
- SHORT-LIVED RADIONUCLIDES
- SUPERNOVA EJECTA
- PROTOPLANETARY DISKS
- NEARBY SUPERNOVA