New calculations of solar spectrum resolve decade-long controversy about the sun's chemical composition
"We found, that according to our analysis the sun contains 26% more elements heavier than helium than previous studies had deduced," explains Magg. In astronomy, such elements heavier than helium are called "metals." Only on the order of a thousandth of a percent of all atomic nuclei in the sun are metals; it is this very small number that has now changed by 26% of its previous value. Magg adds: "The value for the oxygen abundance was almost 15% higher than in previous studies." The new values are, however, in good agreement with the chemical composition of primitive meteorites ("CI chondrites") that are thought to represent the chemical make-up of the very early solar system."
Maria Bergemann says: "The new solar models based on our new chemical composition are more realistic than ever before: they produce a model of the sun that is consistent with all the information we have about the sun's present-day structure—sound waves, neutrinos, luminosity, and the sun's radius—without the need for non-standard, exotic physics in the solar interior."
As an added bonus, the new models are easy to apply to stars other than the sun. At a time where large-scale surveys like SDSS-V and 4MOST are providing high-quality spectra for an ever greater number of stars, this kind of progress is valuable indeed—putting future analyses of stellar chemistry, with their broader implications for reconstructions of the chemical evolution of our cosmos, on a firmer footing than ever before.
The study, "Observational constraints on the origin of the elements. IV: The standard composition of the sun," is published in the journal Astronomy & Astrophysics.
https://phys.org/news/2022-05-solar-spectrum-decade-long-controversy-sun.html
