  We have considered a stationary outflowing envelope from the star accelerated
by the radiative force in arbitrary optical depth case. Introduced
approximations provide satisfactory description of the behavior of the matter
flux with partially separated radiation at arbitrary optical depths. The
obtained system of differential equations provides a continuous transition of
the solution between optically thin and optically thick regions. We
analytically derived approximate representation of the solution at the vicinity
of the sonic point. Using this representation we numerically integrate the
system of equations from the critical point to the infinity. Matching the
boundary conditions we obtain the solution of the describing the problem system
of differential equations. We have discuss in details the problem of the outer
boundary condition. The situation of the photosphere was clarified for the
obtained expanding solution. Theoretical approach submitted in this work could
be useful for self - consistent simulations of the massive stars evolution with
mass loss.
