Prominence intensity (a), Dopplershift (b), and FWHM (c) images (top panels): reconstructed from the 64 Mg II k spectra of raster 5 obtained by IRIS between 12:36 UT and 12:53 UT; Prominence intensity (d), Dopplershift (e), and FWHM (f) images (bottom panels): reconstructed from the Hα spectra obtained by THEMIS around 12:48 UT in two minutes. In panel d the vertical dashed cyan line corresponds to the slit position 42 in the IRIS raster 5 shown above. The horizontal small blue lines indicate the pixels, B, where the profiles have been analysed (Table 4). The pixels A are not visible in Hα image. A movie is available online.