  We report the detection of rapid wavelength and intensity variations of
narrow components in absorption line profiles of the hot galactic supergiant P
Cygni. During most of the time, in one week of observations, there were two
such components present. Although the period of observation is too short for
firm conclusions, the velocity curves do not contradict the photometic period
of 17.3 d. These curves may be interpreted as a double wave, 'swinging in
counterphase'. This observation would suggest the presence of one long wave
over the stellar surface. The waves are possibly gravity waves with wavelengths
of the order of half the stellar radius.
