Lithium abundances in atmospheres of carbon stars estimated with the help of modern lists of spectral lines

We determine lithium abundances in atmospheres of three carbon stars from synthetic spectrum fitting in the λλ 668–674 nm range using the Li I λ 670.8 nm resonance doublet. To produce synthetic spectra, we use a modified list of atomic lines from the VALD database and three alternative line lists of CN and C₂ molecules which are modifications of line lists from the Jorgensen’s website () and from the Kurucz database (1993, CD-ROM nos. 1–23). The spectral lines from these lists were tested by matching synthetic spectra to observed spectra of the sun, Arcturus, and early R star HD 100764. We perform analysis of the blends involving the Li I λ 670.8 nm doublet in spectra of N stars AW Cyg and UX Dra. The lithium abundances in HD 100764, AW Cyg, and UX Dra are estimated to be lgN(Li) ≈ 2, −1.4, and −0.9, respectively. Discrepancies of lithium abundances lgN(Li) obtained with the help of molecular line lists do not seem to exceed 0.2 dex.