Measured oxygen lines, log ϵ(O)_{6300 Å} = 7.30 ± 0.14 and log ϵ(O)_{6364 Å} = 7.46 ± 0.30. Solid red lines show best fits, and dashed blue lines show upper and lower limits of error bars. Cases where [O I] lines have been removed from the linelist are shown with solid gray lines. The strength of CN molecular lines is very sensitive to oxygen abundance. Adopting a lower O abundance will make CN lines in the synthetic spectrum stronger, assuming fixed values of C and N.