The solar beryllium abundance revisited with 3D non-LTE models
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- Published on 08 October 2024
Vol. 690
9. The Sun and the Heliosphere
The solar beryllium abundance revisited with 3D non-LTE models
The solar chemical composition is a key reference in astronomy, serving as a yardstick against which all other cosmic objects may be compared, and as a test of stellar evolution models. In this study, the authors revisit the beryllium abundance in the solar atmosphere by analyzing the Be II 313.107 nm resonance line in the solar spectrum. This is the first work to employ 3D non-LTE models together with a comprehensive calibration technique to account for missing line and continuous opacity. The authors find an abundance that is 0.17 dex lower than the value commonly adopted since 2004. It is also 0.11 dex lower than the initial beryllium abundance in the protosun, as inferred from the CI chondrite class of meteorites, which suggests that material from the solar convective zone has been mixed into the radiative interior, where beryllium ignites at temperatures of around 3.5 million K. This result places stringent constraints on the, as of yet unknown, physical process responsible for the observed depletion, which in turn opens new avenues for detailed studies of the dynamical processes acting in the solar interior and their impact on the evolution of the Sun and solar twins.