SIMBAD references

CNO and metal abundances have been derived for the metal-deficient carbon Mira-type star V CrB using high resolution spectra analyzed by the synthetic spectrum method. The atmosphere was calculated with continuum opacity sources and molecular opacity due to CO, CN, C₂, HCN, C₂H₂ and C₃. V CrB was found to be metal-deficient, with [Fe/H] = -2.12. The CNO abundances are log A(C) = 7.17, log A(N) = 5.3 and log A(O) = 7.13. The carbon isotopic abundance ratio is ¹²C/¹³C = 10.5±5.0. Abundances of the s-process elements are enhanced. The abundance pattern is similar to other late-type CH stars. A comparison of the observed and computed near-infrared spectra indicates the need of improving the C₂H₂ opacity data.