The Atomic Spectra of the Rare Earths: Their Presence in the Sun

Abstract

A summary of the present state of analysis of the first and second spectra of the rare-earth elements is presented with an extensive bibliography. The astrophysical importance of these spectra is stressed. Counts are given of the number of lines of each rare-earth spectrum identified at present in the accessible solar spectrum. Most of them appear only in the singly ionized state; exceptions are Eu i, Tm i?, and Yb i. The possible presence of the strongest laboratory line of Ce iii in the solar spectrum is suggested. If correct, this is the first evidence of a third spectrum line in the accessible range of the solar spectrum (λ > 3000 Å).