A Search for Technetium (Tc II) in Barium Stars

Abstract

The authors searched without success for the lines of Tc II at 2647.02, 2610.00 and 2543.24 Å in IUE spectra of the barium stars HR 5058, ο Vir, and ζ Cap. The lack of Tc II implies that the observed s-process enhancements were produced more than half a million years ago and supports the suggestion that the spectral peculiarities of barium stars are probably related to the binary nature of the stars.