A model for selective line-driven acceleration of ions in the solar   winds of OB-type stars occurring via the nonlinear process of stimulated   Rayleigh scattering
  A conceptually novel model - one in which stimulated (i.e. induced) resonance Rayleigh scattering causes ions of select species to become accelerated to very high terminal velocities in the solar winds of OB-type stars - is proposed to explain the general appearance of so-called P Cygni profiles that often dominate the vacuum ultraviolet (VUV) spectra of such stars. The high rate of stimulated scattering enables ions of the resonant species in the solar wind to become accelerated to terminal velocities as high as 1000 km/sec. Since stimulated scattering processes are characterized by pump power thresholds, the model readily explains why only select species are accelerated to very high velocities in a given star's solar wind, and also why a dramatic P Cygni profile for a given ion species can often discontinuously be present or absent when spectra of stars varying only slightly in spectral type are compared. 
P.P. Sorokin (1) and J.H. Glownia (2) ((1) IBM Research Division, (2)   Los Alamos National Lab)