Observations of the X-ray Pulsar GX 301-2 with the ART-P Telescope of   the Granat Observatory
  The variability of the X-ray flux from the pulsar GX 301-2 is analyzed by using data from the ART-P telescope of the Granat Observatory. The intensity variations with time scales of several thousand seconds are studied at various orbital phases. The high-state flux from the source exceeds its low-state flux by as much as a factor of 10. The hardness and spectrum of the source are shown to change greatly with its intensity. These intensity variations are most likely caused by substantial inhomogeneities in the stellar wind from the companion star. 
S.S.Tsygankov (1), A.A.Lutovinov (1), S.A.Grebenev (1), M.R.Gilfanov   (1,2), R.A.Sunyaev (1,2) ((1) Space Research Institut...