Aluminum-26 in the early solar system: Fossil or fuel?
Abstract
The isotopic composition of Mg was measured in different phases of a Ca-Al-rich inclusion in the Allende meteorite. Large excesses of ²⁶Mg of up to 10% were found. These excesses correlate strictly with the ²⁷Al/²⁴Mg ratio for four coexisting phases with distinctive chemical compositions. Models of in situ decay of ²⁶Al within the solar system and of mixing of interstellar dust grains containing fossil ²⁶Al with normal solar system material are presented. The observed correlation provides definitive evidence for the presence of ²⁶Al in the early solar system. This requires either injection of freshly synthesized nucleosynthetic material into the solar system immediately before condensation and planet formation, or local production within the solar system by intense activity of the early sun. Planets promptly produced from material with the inferred ²⁶Al/²⁷Al would melt within ~3 x 10⁵ yr.
Additional Information
We thank J. H. Chen and G. R. Tilton for their generosity in providing us with this important sample. We gratefully acknowledge the advice and aid of R. A. Schmitt and his associates, especially R. Conard, in setting up the neutron activation analyses. Continuing encouragement from T. Tombrello is appreciated. We thank A. L. Albee for ready access to the microprobe facility. Comments from D. N. Schramm on the manuscript were helpful. This work was supported by NSF PHY 76-02724 and by NASA NGL-05-002-188.Additional details
- Eprint ID
- 118679
- Resolver ID
- CaltechAUTHORS:20230105-146138400.1
- PHY 76-02724
- NSF
- NGL-05-002-188
- NASA
- Created
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2023-01-05Created from EPrint's datestamp field
- Updated
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2023-01-05Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Division of Geological and Planetary Sciences
- Other Numbering System Identifier
- 2811