The solar beryllium abundance.
Abstract
An interpretation of high-resolution centerlimb observations of the Be II resonance lines in the solar spectrum is given. It is shown that to account for the observed spectrum, it is necessary to allow for (1) a source of additional opacity in the UV continuum which was derived empirically for the HSRA (Harvard Smithsonian Reference Atmosphere) and revised Holweger (1974) models and (2) departures from LTE in the Be I-Be II system. It is found that the 2p(3)P(0) metastable level of Be I is significantly underpopulated and that beryllium is more ionized than expected in the case of local thermodynamic equilibrium. The kinetic equilibrium calculations yield a logarithmic beryllium abundance of approximately 1.15 (on the basis of a logarithmic hydrogen abundance of 12.00), which is in agreement with previous determinations based on the LTE assumption.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1975
- Bibcode:
- 1975A&A....42...37C
- Keywords:
-
- Abundance;
- Beryllium;
- Solar Spectra;
- Ultraviolet Spectra;
- Astronomical Models;
- High Resolution;
- Line Spectra;
- Metal Ions;
- Metastable State;
- Opacity;
- Spectroheliographs;
- Thermodynamic Equilibrium;
- Solar Physics