He-like triplet lines of O VII (top), N VI (middle), and Ne IX (bottom) during the dip (black histogram, 2.7 ks) and during the bright time intervals (light shadings, 19 ks). The blue crosses mark bad pixels with suspicious or invalid flux values. Dotted vertical lines mark the resonance (r: 1s2p ¹P₁) intercombination (i: 1s2p ³P₁), and forbidden (f: 1s2s ³S₁) lines. In thebottom panel, potentially blending lines of Fe XIX are also marked and labelled. All spectra are smoothed with a Gaussian kernel of 0.03 Å, the instrumental broadening, for better visualisation. See Sect. 3.2.4 for discussion.