CNO abundances from pre-maximum spectra of Nova Cygni 1975

Coude spectra of Nova Cygni 1975 have been compared with LTE synthetic spectra and abundances derived for carbon, nitrogen, and oxygen. It was found that while carbon is not enhanced over the solar value, nitrogen and oxygen are substantially over-abundant by factors of at least 30 and 10, respectively. These results can be compared with analyses performed on the nebular spectrum.