Panel a): a 131 Å image showing three separate components of the expanding CME labelled as C1, C2 and C3. Panels b) and c): 211 Å images with the CME and the leading edge which precedes it indicated in orange in panel b) and red in the difference image in panel c). The solid green line in panel b) indicates the position of the slit used to analyse the expanding feature ahead of the CME.