Hostname: page-component-7c8c6479df-hgkh8 Total loading time: 0 Render date: 2024-03-29T13:17:02.739Z Has data issue: false hasContentIssue false

12C/13C in atmospheres of red giants and peculiar stars

Published online by Cambridge University Press:  23 December 2005

Yakiv V. Pavlenko
Affiliation:
Main Astronomical Observatory of National Academy of Sciences, 27 Zabolotnoho, Kyiv-127, 03680 Ukraine email: yp@mao.kiev.ua Centre for Astrophysics Research, University of Hertfordshire, College lane, Hatfield, AL10 9AB, UK email: yp@star.herts.ac.uk
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We determine the carbon isotopic ratios in the atmospheres of some evolved stars in both globular clusters and the disk of our Galaxy. Analysis of 12CO and 13CO bands at 2.3 micron was carried out using fits to observed spectra of red giants and Sakurai's object (V4334 Sgr). The dependence of theoretical spectra on the various input parameters was studied in detail. The computation of model atmospheres and a detailed abundance analysis was performed in a self-consistent fashion. A special procedure for determining the best fits to observed spectra was used. We show, that globular cluster giants with [Fe/H]$\,{<}\,{-}$1.3 have a low 12C/13C = 4 ±1 abundance ratios. In the spectra of Sakurai's object (V4334 Sgr) taken between 1997-98, the 2.3 micron spectral region is veiled by hot dust emission. By fitting UKIRT spectra we determined 12C/13C = 4 ±1 for the July, 1998 spectrum. CO bands in the spectra of ultracool dwarfs are modelled as well.

Type
Contributed Papers
Copyright
© 2005 International Astronomical Union