Amplitude variation with time for g₁, g₈, g₄ and g₇ (top to bottom) of ALS 10705. The individual points were computed by co-adding the fits to all frequencies found by LS belonging to each group, and then the absolute value was plotted. The upper envelope of each group, therefore, represents the amplitude variations seen in the lower panel of Fig. 2 and illustrates the various correlations described in the text.