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   PR #    74
   1. The precise X-ray spectroscopic observation is carried out in order
   to determine whether the X-ray emission mechanism is thermal or
   non-thermal. Especially, we should pay much attention to line
   emissions and absorption features predicted by many models. We also
   investigate the existence of hard component.2. The time variation in
   X-ray light curve is examined. Many theoretical study the instability
   of radiative driven stellar winds with a time scale of 10^2-10^5 sec
   (e.g. Carlberg 1980; Owocki and Rybicki 1984).
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