The detection of a circumstellar shell around P Cygni by direct CCD imaging

Claus Leitherer, Franz-Josef Zickgraf
1987 Symposium - International astronomical union  
The star P Cygni (=HD 193237) is the proto-type of a class of stars with peculiar spectra, the so-called P-Cygni-stars (or Luminous Blue Variables). They are characterized by extreme mass-loss characteristics and wind densities surpassed only by the winds of Wolf-Rayet stars.
doi:10.1017/s0074180900156906 fatcat:lv57o6zlc5adtgqbylxh7eq33y