The normal points in intensities are suitable for the determination of photo-
metric elements using the W&D method. In order to decrease the number of
free parameters, we assumed Teff determined in Section 2.2,
a logaritmic limb-
darkening law and theoretically predicted values of monochromatic and bolo-
metric coefficients of limb-darkening given by van Hamme (1993), gravitational
darkening and bolometric albedo appropriate for radiative envelopes given by
Rucinski (1973). Synchronous rotation and zero eccentricity were assumed. Ap-
proximate atmosphere option was used. All light curves in the V BLU (for GW
Car also W ) passbands were solved simultaneously. The differential corrections
code was run until the output corrections were smaller than the standard errors
σ of the elements. The differential corrections converged rather slowly. We had
to perform up to 100 steps for one solution.