HD 209621: Abundances of neutron-capture elements

Abstract

High resolution spectra obtained from the Subaru Telescope High Dispersion Spectrograph have been used to update the stellar atmospheric parameters and metallicity of the star HD 209621. We have derived a metallicity of [Fe/H] = -1.93 for this star, and have found a large enhancement of carbon and of heavy elements, with respect to iron. Updates on the elemental abundances of four s-process elements (Y, Ce, Pr, Nd) along with the first estimates of abundances for a number of other heavy elements (Sr, Zr, Ba, La, Sm, Eu, Er, Pb) are reported. The stellar atmospheric parameters, the effective temperature, Teff, and the surface gravity, log g (4500 K, 2.0), are determined from LTE analysis using model atmospheres. Estimated [Ba/Eu] = +0.35, places the star in the group of CEMP-(r+s) stars; however, the s-elements abundance pattern seen in HD 209621 is characteristic of CH stars; notably, the 2nd-peak s-process elements are more enhanced than the first peak s-process elements. HD 209621 is also found to show a large enhancement of the 3rd-peak s-process element lead (Pb) with [Pb/Fe] = +1.88. The relative contributions of the two neutron-capture processes, r- and s- to the observed abundances are examined using a parametric model based analysis, that hints that the neutron-capture elements in HD 209621 primarily originate in s-process.

16 pages,8 figures. Accepted for publication in MNRAS

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Cited by in corpus (8)

• Observational Constraints on First-Star Nucleosynthesis. I. Evidence for Multiple Progenitors of CEMP-no Stars
• Learning about the intermediate neutron-capture process from lead abundances
• Constraints of the physics of low-mass AGB stars from CH and CEMP stars
• Chemical analysis of CH stars - III: Atmospheric parameters and elemental abundances
• Probing the nucleosynthetic contribution of low-metallicity, low-mass star companions of CEMP stars
• Evidence of V-band polarimetric separation of carbon stars at high Galactic latitude
• Abundance analysis of s-process enhanced barium stars
• Chemical analysis of a carbon-enhanced very metal-poor star: CD-27 14351