Fit examples of the Hα line with the observed quiescent spectrum subtracted. The data is shown in grey, the fit components are shown in green, blue, and red, and the resulting fit is shown in black. The data contains additional narrow short-lived line components, which are not fitted here, but are indicated by arrows for the two most complicated spectra at 3:59 UT. Between 3:00 and 3:01 UT the fit switches to another line component. The second spectrum in the upper row shows the flare onset. In the last two spectra one can note an absorption line at about 6563 Å, which is caused by the dimming of a preflare line component and not caused by the flare.