Calculated spectral energy distributions (Eddington flux H_ν in cgs units) versus wavelength of our current best model (A^∗) of R136a3. The spectrum contains, in addition to the typical P-Cygni profiles of the strong resonance lines, numerous absorption and emission lines above and below the continuum curve, illustrating that we are looking down into an extended photosphere similar to that of an O star. Thus, the behavior of the spectral energy distribution clearly shows that this model has an optically thin wind in the optical and observable UV continuum²⁵.