Comparison of the spectra at 45 (blue) and 109 (magenta) days. We note the increase in the relative Hα flux and the much deeper absorption features in the day 109 spectrum. The dotted blue and red vertical lines show the wavelengths corresponding to ±15 000 km s⁻¹. The spectra have been smoothed by a third order Savitzky–Golay filter, with windows of 5 and 11 pixels, respectively.