Resumo

SUMANGALA RAO, S.  e  GIRIDHAR, Sunetra. Chemical compositions of RV tauri stars and related objects. Rev. mex. astron. astrofis [online]. 2014, vol.50, n.1, pp.49-65. ISSN 0185-1101.

We have undertaken a comprehensive abundance analysis for a sample of relatively unexplored RV Tauri and RV Tauri like stars to further our understanding of post-Asymptotic Giant Branch (post-AGB) evolution. From our study based on high resolution spectra and a grid of model atmospheres, we find indications of mild s-processing for V820 Cen and IRAS 06165+3158. On the other hand, SU Gem and BT Lac exhibit the effects of mild dust-gas winnowing. We have also compiled the existing abundance data on RV Tauri objects and find that a large fraction of them are afflicted by dust-gas winnowing and aided by the present work, we find a small group of two RV Tauris showing mild s-process enhancement in our Galaxy. With two out of three reported s-process enhanced objects belonging to RV Tauri spectroscopic class C, these intrinsically metal-poor objects appear to be promising candidates to analyse the possible s-processing in RV Tauri stars.

Palavras-chave : stars [abundances]; stars [AGB and post-AGB]; stars [variables].

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