Chemical analysis of three barium stars: HD 51959, HD 88035, HD 121447

Abstract

We present elemental abundance results from high-resolution spectral analysis of three nitrogen-enhanced barium stars. The analysis is based on spectra obtained with the fibre- fed extended range optical spectrograph attached to 1.52 m telescope at European Southern Observatory, Chile. The spectral resolution is R ∼ 48,000 and the spectral coverage spans from 3500 to 9000Å . For the objects HD 51959 and HD 88035, we present the first-time abundance analyses results. Although a few studies are available in literature on the object HD 121447, the results are significantly different from each other. We have therefore carried out a detailed chemical composition study for this object based on a high-resolution spectrum with high S/N ratio, for a better understanding of the origin of the abundance patterns observed in this star. Stellar atmospheric parameters, the effective temperature, surface gravity, microturbulence, and metallicity of the stars are determined from the local thermodynamic equilibrium analysis using model atmospheres. The metallicities of HD 51959 and HD 88035 are found to be near- solar; they exhibit enhanced abundances of neutron-capture elements. HD 121447 is found to be moderately metal-poor with [Fe/H] =− 0.65. While carbon is near-solar in the other two objects, HD 121447 shows carbon enhancement at a level, [C/Fe] = 0.82. Neutron-capture elements are highly enhanced with [X/Fe] > 2 (X: Ba, La, Pr, Nd, Sm) in this object. The α - and iron-peak elements show abundances very similar to field giants with the same metal- licity. From kinematic analysis all the three objects are found to be members of thin disc population with a high probability of 0.99, 0.99, and 0.92 for HD 51959, HD 88035, and HD 121447, respectively.