Detailed rms and flux spectra from day 2 and day 6. The four panels show the flux (top) and fractional rms (bottom) spectra for day 2 (left) and day 6 (right). The top row presents the behaviour of He I-5876, while Hα is shown in the bottom row. The rms spectra show an inverted shape compared to the flux spectra, especially in the presence of P-Cygni profiles. Statistical errors are smaller than the data points. Vertical dashed lines indicate the laboratory wavelength of the corresponding transition. Light yellow boxes highlight the regions affected by interstellar bands.