ON THE RELATIVE LUMINOSITIES OF THE STARS IN THE WOLF-RAYET BINARY V444-CYGNI

A new spectroscopic estimate of the luminosity ratio q = L(WR)/L(O6) i s obtained from the dilution of the absorption lines of the O6V-III co mponent in the WR eclipsing binary V 444 Cygni (WN5+O6). We find q = 0 .60 +/- 0.06 for the range lambda lambda 4000 - 6000 Angstrom and q = 0.56 +/- 0.13 from IUE spectra. This clearly indicates that the light of the O6 dominates the combined light of V 444 Cyg. This result is in strong contradiction with the value q = 3.1 derived from the light cu rve solution for V 444 Cyg (model with T-eff = 40000 K for the O-star component) by Hamann and Schwarz (1992), but agrees with the light cur ve solutions obtained previously by Cherepashchuk (1975) and Cherepash chuk et al. (1984). The discrepancy can be explained if the model of a homogeneous extended atmosphere for WR stars applied by Hamann and Sc hwarz for the determination of q from the emission lines of He I and H e II is not applicable. Clumpy structure of WR winds proposed in earli er papers (Cherepashchuk et al. 1984; Moffat et al. 1988) should be mo re applicable.