The solar Na/Ca and S/Ca ratios: A close comparison with carbonaceous chondrites
Abstract
Solar abundances based on recent laboratory oscillator strengths confirm the relationship between solar matter and carbonaceous chondrites. Within spectroscopic uncertainties (typically ±40%) these meteorites contain refractory and volatile elements in solar proportions. Significant improvement of accuracy at present seems restricted to a few abundant elements having reliable quantum-mechanical oscillator strengths, and necessitates strictly differential spectrum analysis. Taking this into account, the solar abundance ratios Na/Ca and S/Ca have been determined to an accuracy of ±15%. The results are: Na/Ca= 0.91and S/Ca= 6.8. These volatile/refractory ratios just match type 1 carbonaceous chondrites, but contrast with other types. These and related interstellar abundance features place constraints on the condensation process and a potential heterogeneity of the solar nebula. There is evidence that no drastic pre-solar separation of interstellar gas and grains has occurred, but minor imbalance may be a common mechanism co-determining stellar metal content.
- Publication:
-
Earth and Planetary Science Letters
- Pub Date:
- February 1977
- DOI:
- 10.1016/0012-821X(77)90116-9
- Bibcode:
- 1977E&PSL..34..152H
- Keywords:
-
- Abundance;
- Calcium;
- Carbonaceous Chondrites;
- Sodium;
- Solar Atmosphere;
- Sulfur;
- Atmospheric Composition;
- Interstellar Gas;
- Mass Ratios;
- Spectrum Analysis