S-process-enriched cool stars with and without technetium - Clues to asymptotic giant branch and binary star evolution

Abstract

view Abstract Citations (88) References (45) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS S-Process--Enriched Cool Stars with and without Technetium: Clues to Asymptotic Giant Branch and Binary Star Evolution Smith, Verne V. ; Lambert, David L. Abstract High-resolution spectra at λ4260 have been obtained for 40 stars of type MS or S to search for the presence of Tc I. In addition, previously published Tc surveys provide an additional 18 stars for a total sample of 58 MS or S stars. Most of these stars have also been observed in Zr I, Y II, La II, and Nd II lines. These stars show general s-process abundance enhancements. Of the total sample, 38% of these s-process-enriched stars do not show Tc. The authors suggest that the MS and S stars are composed of two major groups: (1) Tc-containing stars which are currently thermally pulsing AGB stars undergoing third dredge-up and (2) Tc-poor stars which represent the coolest members of the barium star class, where s-process enrichment is probably the result of binary mass transfer in the past. Publication: The Astrophysical Journal Pub Date: October 1988 DOI: 10.1086/166738 Bibcode: 1988ApJ...333..219S Keywords: Asymptotic Giant Branch Stars; Binary Stars; Cool Stars; Stellar Composition; Stellar Evolution; Technetium; Barium; M Stars; S Stars; Stellar Atmospheres; Stellar Spectra; Astrophysics; STARS: ABUNDANCES; STARS: BA II; STARS: BINARIES; STARS: LATE-TYPE; STARS: S-TYPE full text sources ADS | data products SIMBAD (40)