Some of the multi-Gaussian fits for one of the dates (JD 2 455 674.82443). The normalised, continuum-subtracted observed spectra are displayed as thick black lines. Individual Gaussian components are plotted as thin lines (colours: green, red, blue, cyan). The combined fit is plotted as a magenta thick line. The zero velocities of the central line are also marked with a vertical dotted line. The plots are labelled with the line(s) elements and wavelength. Note that the very complex shape of the continuum around the Fe I 5269/70 Å lines is better fitted by two strong Gaussians, one in emission and the other in absorption (partly out of the figure). These BC have no physical meaning/interpretation, but allow us to extract properly the strong NC of both lines.