Solar System Abundances and Condensation Temperatures of the Elements

TLDR

Standard solar models that include helium and heavy‑element settling show that photospheric abundances differ from protosolar values, which represent solar‑system abundances. The study aims to derive protosolar elemental and isotopic abundances from photospheric data while discussing meteoritic and solar abundances of selected elements. The authors compile solar photospheric and CI chondrite meteoritic abundances, select the most reliable photospheric values, and use these tables to calculate self‑consistent condensation temperatures for all elements. The study finds photospheric mass fractions of X = 0.7491, Y = 0.2377, Z = 0.0133 (Z/X = 0.0177, lower than the previously used 0.0245) and protosolar fractions of X₀ = 0.7110, Y₀ = 0.2741, Z₀ = 0.0149.

Abstract

Solar photospheric and meteoritic CI chondrite abundance determinations for all elements are summarized and the best currently available photospheric abundances are selected. The meteoritic and solar abundances of a few elements (e.g., noble gases, beryllium, boron, phosphorous, sulfur) are discussed in detail. The photospheric abundances give mass fractions of hydrogen (X = 0.7491), helium (Y = 0.2377), and heavy elements (Z = 0.0133), leading to Z/X = 0.0177, which is lower than the widely used Z/X = 0.0245 from previous compilations. Recent results from standard solar models considering helium and heavy-element settling imply that photospheric abundances and mass fractions are not equal to protosolar abundances (representative of solar system abundances). Protosolar elemental and isotopic abundances are derived from photospheric abundances by considering settling effects. Derived protosolar mass fractions are X0 = 0.7110, Y0 = 0.2741, and Z0 = 0.0149. The solar system and photospheric abundance tables are used to compute self-consistent sets of condensation temperatures for all elements.