[HN Gopher] Calculations resolve controversy about the sun's che...
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       Calculations resolve controversy about the sun's chemical
       composition
        
       Author : PaulHoule
       Score  : 29 points
       Date   : 2022-05-23 15:27 UTC (7 hours ago)
        
 (HTM) web link (phys.org)
 (TXT) w3m dump (phys.org)
        
       | kurthr wrote:
       | "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.
        
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       (page generated 2022-05-23 23:01 UTC)