Published online by Cambridge University Press: 12 April 2016
8 white dwarfs of spectral type λ4670, LP 93-21, EG182, BPM 27606, EG82, G257-38, EG148, G99-37 and L97-3, with more or less well observed carbon bands in their spectra, have been analyzed by detailed model atmosphere techniques. For the very strong band stars the blanketing effect of the molecular band systems of the Swan band and the Deslandres-d’Azambuja band had to be included in the computation of the models. The best fit of the fluxes with scanner observations and spectra is obtained for abundance ratios of 103 ≤ He/H ≤ 105, 800 ≤ He/C ≤ 5000, with LP 93-21 being the most carbon-rich object. The results are summarized in Table 1.