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Author Giridhar, S. ♦ Lambert, D. L. ♦ Gonzalez, G.
Source Indian Institute of Astrophysics
Content type Text
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics
Subject Keyword Stars: abundances ♦ Stars: agb and post-agb ♦ Stars: variables
Description Chemical compositions are derived from high-resolution spectra for three stars classed as SRd variables in the General Catalogue of Variable Stars. These stars are shown to be metal-poor supergiants: WY And with [Fe/H]=-1.0, VW Eri with [Fe/H]=-1.8, and UW Lib with [Fe/H]=-1.2. Their compositions are identical to within the measurement errors to the compositions of subdwarfs, subgiants, and less evolved giants of the same [Fe/H]. The stars are at the tip of the first giant branch or in the early stages of evolution along the asymptotic giant branch (AGB). There is no convincing evidence that these SRd variables are experiencing thermal pulsing and the third dredge-up on the AGB. The SRd variables appear to be at the cool limit of the sequence of RV Tauri variables.
ISSN 00046280
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Institution The Astronomical Society of the Pacific
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