Contrast Enhancement of Binary Star System Using an Optical Vortex   Coronagraph
  Using an optical vortex coronagraph and simple adaptive optics techniques we have made the first convincing demonstration of an optical vortex coronagraph that is coupled to a star gazing telescope. In particular we suppressed by 97% the primary star of a barely resolvable binary system, Cor Caroli, having an effective angular separation of only 1.4 lambda/D. The secondary star suffered no suppression. 
Grover A. Swartzlander, Jr., Erin L. Ford, Rukiah S. Abdul-Malik,   Laird M. Close, Mary Anne Peters, David M. Palacios, Dan...