Main frames showing the event on April 25, and 26, 2021. At the top, a sequence of eight frames of the Metis pB base difference. The base frame is at 15:20 UT. At the bottom, the bright event observed in H I Ly-α is visible in nearly simultaneous base differences, using the base frame at 15:28 UT. The CME structure is highlighted with arrows in frames (a)–(c), which contain respectively front, cavity and bright core. In UV frames (i), (l), and (m), the same structures are barely visible. In frame (n), the CME bright core and features are both very intense and easily visible in both channels and appear separate. The temporal evolution in both channels is available as an online movie (pb_20210425.mp4 and UV_20210425.mp4).