Comments on the superluminal motion in Cygnus X-3
  Following the recent discovery that Cyg X-3 exhibits superluminal motion, the implications of superluminal expansion and contraction are investigated. We propose that the effect is due to either a propagating photon pattern or to outwardly moving shells illuminated by an intense beam of radiation. 
R.N. Ogley (1), S.J. Bell Burnell (1) and S.J. Newell (2) ((1) The   Open University, UK, (2) NRAL, Jodrell Bank, UK)