"Early studies of how the spectra of stars are produced had relied on something known as local thermal equilibrium. They had assumed that locally, energy in eac

"Early studies of how the spectra of stars are produced had relied on something known as local thermal equilibrium. They had assumed that locally, energy in each region of a star's atmosphere has time to spread out and reach a kind of equilibrium. This would make it possible to assign to each such region a temperature, which leads to a considerable simplification in the calculations. But as early as the 1950s, astronomers had realized that this picture was oversimplified. Since then, more and more studies incorporated so-called Non-LTE calculations, dropping the assumption of local equilibrium." The group led by Ekaterina Magg, Maria Bergemann and colleagues leaders in non-LTE calculations resolved a contradiction in solar abundance finding that denser (than helium) materials accounted for 26% more (less than 2% total and each <0.6%) than previous calculations.