Synthetic line profiles for the UV resonance doublet of O VI, for the same stellar model and different shock distributions as in Fig. 13 (M1, upper left), and for three other models (M2 to M4) differing in mass-loss rate and clumping properties (see Table. 5). Same color coding as in Fig. 15. Profiles from the smooth-wind models M1 and M2 are close to being identical, though mass-loss rates differ by a factorof four. All spectra have been calculated with a depth dependent “micro-turbulence” (proportional to v(r), with a minimum of 15 km s⁻¹, and a maximum of 0.1v_∞), and convolved with v sin i = 220 km s⁻¹. For comparison, the observed COPERNICUS spectrum (at a resolution of 0.2 Å, Snow & Jenkins 1977) is displayed in dark green. The dotted lines at the top display the rest-frame frequencies of the doublet components. The absorption feature around 1215 Å, visible in all synthetic spectra without significant O VI contribution, is stellar Lyβ. Model M1 and M4 and corresponding spectra (for f_X = const.) are very similar to those displayed (and discussed) by Zsargó et al. (2008) in their Fig. 1.