The C-12/C-13 and O-16/O-18 ratios in the solar photosphere
Abstract
The abundances of C-12, C-13 and O-18 in the solar photosphere have been measured from more than 900 lines of the fundamental vibration-rotation bands of isotopically substituted CO species. It is found that log N(C-12) = 8.71 + or - 0.10, C-12/C-13 = 84 + or - 5, and O-16/O-18 = 440 + or - 50, i.e., the solar and terrestrial isotopic ratios are essentially identical. These results, together with the known abundances of lighter isotopes, constrain unorthodox models of the sun's evolution which require the surface layers to have been subjected to high temperatures. A requirement that the derived molecular abundance be independent of the excitation potential and wavelength is not met by all empirical model solar atmospheres. The Holweger and Muller (1974) model meets the requirement and the Vernazza, Avrett and Loeser (1976) model does not.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 1987
- DOI:
- 10.1093/mnras/224.1.237
- Bibcode:
- 1987MNRAS.224..237H
- Keywords:
-
- Carbon Isotopes;
- Line Spectra;
- Oxygen Isotopes;
- Solar Atmosphere;
- Abundance;
- Balloon Flight;
- Carbon Monoxide;
- Fourier Transformation;
- High Temperature;
- Solar System;
- Solar Physics