Gray‐scale image of the deviations from the average Hα and He I λ6678 line profiles as a function of both time and line position for the 1987 January 5 observations. Darker shades indicate a depression relative to the mean line profile, while bright regions correspond to places at which the profile is stronger than the mean. The time axis runs from top to bottom and represents a total of 10 individual spectra. The average spectrum from this night is plotted below the image to provide a line position reference.