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tokens: panel d shows the period from cosine fitting, panels e, f, g present the amplitude, the phase, and the spectral power from the cosine fitting, and panel h shows the H α intensity. 3.2.1. Periods We detect oscillatory motions with periods between 5 and 80 min (Fig. 2 c). The shorter periods (5 to 40 min) have a local significance level of around 99%; they last only two to four times their periods and are visible in small areas. It would be interesting to find out where and when they occur, but this is beyond the scope of this study. Here, we concentrate our work on the long periods between 40 and 80 min which were already detected in Paper I. We find that the prominence does not oscillate as a block at these long periods. We identify four main oscillatory areas with a high spectral power (see Fig. 2 g and Table 1 ). We select these four areas with high spectral power and overplot their contours on all the panels of Fig. 2 . For each area, we calculate the mean value of the oscillatory parameters (see Table 1 ). The value of the spectral power in relative units is around 40. The mean oscillation period for areas A1 and A2 is close to 65 min with the two methods (Scargle and cosine fit methods). For area A3 we obtain a value of 45 min. We exclude area A4 from further analysis because of the non-uniform pattern in period, amplitude, and phase distribution, which is a hint of the bad fit of the cosine curve due to high noise. Additionally, the periods calculated using the two methods are significantly different. We may note that a similar period value of 65 min is commonly observed for longitudinal oscillations in prominences ( Luna et al. 2018 ). In areas A1, A2, and A3, the period is nearly uniform (Fig. 2 c). The mean amplitude of the oscillations is between 0.70 km s −1 and 1.43 km s −1 , values larger than the estimation of the error bars. However, higher amplitude values are present in the selected areas, reaching locally 3 km s −1 (Fig. 2 e). We notice another region with even higher amplitude located near the pixel coordinates ( x = 40, y = 150), but the signal has a relatively low spectral power value and is too small to be treated as an oscillating feature. Table 1. Mean oscillatory parameters calculated for areas with the highest spectral power (see Fig. 2 ). 3.2.2. Phase Fitted phase is presented in Fig. 2 f. In areas A2 and A3 at the bottom of the prominence the phase has the same value in each area. Additionally, in each of these two regions the period values are very similar (see Figs. 2 c and d), and the spectral power reaches local peaks (see Fig. 2 g). On the contrary, in area A1 the period and amplitude are similar but the phase does not have a uniform value; it shows a continuous transition between − π and 0 radians. This may be interpreted as the passage of a wavefront of a MHD wave ( Schmieder et al. 2013 ; Ofman et al. 2015 ). The colour gradient gives the direction of the propagation of the wave in the POS. This is