The chemical composition of the mild barium star HD 202109

We present chemical abundances of the mild barium star HD 202109 ( ζ Cyg) determined from the analysis of a spectrum obtained by using the 2-m telescope at the Peak Terskol Observatory and a high-resolution spectrometer with $R=80\,000$, signal to noise ratio >100. We also present the atmospheric parameters of the star determined using various methods including iron-line abundance analysis. For line identifications, we use whole-range synthetic spectra computed from Kurucz's database and the latest lists of spectral lines. Among the determined abundances of 51 elements, those of P, S, K, Cu, Zn, Ge, Rb, Sr, Nb, Mo, Ru, Rh, Pd, In, Sm, Gd, Tb, Dy, Er, Tm, Hf, Os, Ir, Pt, Tl, and Pb were not investigated previously. Assuming that the overabundance pattern of Ba stars is due to binary accretion, the observed abundance pattern of the neutron-capture process elements in HD 202109 can be explained by combining the AGB star nucleosynthesis and the wind accretion scenario.