On Purple Mountain Halpha observations of SS 433
  In this brief note I draw attention to the structure of the stationary Halpha line as a function of orbital phase, using a data set compiled over some years. These data are compared with a set of nightly observations over some 2 orbits. The structures are very similar and this is highly relevant to the question of persistence and stability of spectral features which have been attributed to a circumbinary disk. 
M G Bowler
astro-ph.GA