1995A&A...293..142C

A new spectroscopic estimate of the luminosity ratio q=L_WR/L_O6 is obtained from the dilution of the absorption lines of the O6V-III component in the WR eclipsing binary V444 Cygni (WN5+O6). We find q=0.60±0.06 for the range λλ4000-6000A and q=0.56±0.13 from IUE spectra. This clearly indicates that the light of the O6 dominates the combined light of V444 Cyg. This result is in strong contradiction with the value q=3.1 derived from the light curve solution for V444 Cyg (model with T_eff=40000K for the O-star component) by Hamann & Schwarz (1992A&A...261..523H), but agrees with the light curve solutions obtained previously by Cherepashchuk (1976SvA....19..727C) and Cherepashchuk et al. (1984ApJ...281..774C). The discrepancy can be explained if the model of a homogeneous extended atmosphere for WR stars applied by Hamann & Schwarz for the determination of q from the emission lines of He I and He II is not applicable. Clumpy structure of WR winds proposed in earlier papers (Cherepashchuk et al. 1984ApJ...281..774C; Moffat et al. 1988ApJ...334.1038M) should be more applicable.