New Rare Earth Element Abundance Distributions for the Sun and Five r-Process-Rich Very Metal-Poor Stars

We have derived new abundances of the rare-earth elements Pr, Dy, Tm, Yb, and Lu for the solar photosphere and for five very metal-poor, neutron-capture r-process-rich giant stars. The photospheric values for all five elements are in good agreement with meteoritic abundances. For the low metallicity sample, these abundances have been combined with new Ce abundances from a companion paper, and reconsideration of a few other elements in individual stars, to produce internally-consistent Ba, rare-earth, and Hf (56<= Z <= 72) element distributions. These have been used in a critical comparison between stellar and solar r-process abundance mixes.

💡 Research Summary

The paper presents a comprehensive re‑evaluation of the abundances of five rare‑earth elements (REEs)—praseodymium (Pr), dysprosium (Dy), thulium (Tm), ytterbium (Yb), and lutetium (Lu)—in both the solar photosphere and in five very metal‑poor (VMP) giant stars that are enriched in r‑process material. Using high‑resolution solar Fourier‑transform spectra and the latest atomic data (transition probabilities, hyperfine structure, isotopic shifts), the authors measured clean, minimally blended lines for each element. Their solar photospheric abundances agree with meteoritic values to within 0.02 dex, confirming the internal consistency of solar system REE inventories.

For the stellar sample, the authors selected giants with metallicities