Bibcode
Purandardas, M.; Goswami, A.; Goswami, P. P.; Shejeelammal, J.; Masseron, T.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 486, Issue 3, p.3266-3289
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7
2019
Citations
21
Refereed citations
21
Description
Elemental abundances of CH stars can provide observational constraints
for theoretical studies on the nucleosynthesis and evolution of low- and
intermediate-mass stars. However, available abundance data in literature
are quite scanty. In our pursuit to generate a homogeneous data base of
elemental abundances of CH stars we have performed a detailed chemical
abundance study for a sample of 12 potential CH star candidates based on
high-resolution spectroscopy. We present first time abundance analysis
for the objects HE0308-1612, CD-281082, HD30443, and HD87853. For the
other objects, although limited information is available, detailed
chemical composition studies are missing. Our analysis shows CD-281082
to be a very metal-poor object with [Fe/H] = -2.45 and enriched in
carbon with [C/Fe] = 2.19. With a ratio of [Ba/Eu] ˜ 0.02 the star
satisfies the classification criteria of a CEMP-r/s star. The objects
CD-382151 with [Fe/H] = -2.03 and HD30443 with [Fe/H] ˜ -1.68 are
found to show the characteristic properties of CH stars. HE0308-1612 and
HD87853 are found to be moderately metal poor with [Fe/H] ˜ -0.73;
while HE0308-1612 is moderately enhanced with carbon ([C/Fe] ˜
0.78) and shows the spectral properties of CH stars, the abundance of
carbon could not be estimated for HD87853. Among the two moderately
metal-poor objects, HD87080 ([Fe/H] = -0.48) shows near solar carbon
abundance, and HD176021 ([Fe/H] = -0.63) is mildly enhanced in carbon
with [C/Fe] = 0.52. HD176021 along with HD202020 a known binary, exhibit
the characteristic properties of CH stars as far as the heavy element
abundances are concerned. Five objects in our sample show spectral
properties that are normally seen in barium stars.
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