Example low-resolution spectra for three selected epochs with the most prominent molecular band features identified. Normalisation of the calibrated spectra is performed at λ = 7560 Å. Black dotted lines exemplary mark the pseudo-continuum for measuring the (pseudo-)equivalent widths of the VO band structures B-X(1,0) and B-X(0,0) in the 2020 spectrum. The NOT transmission curves of the ALFOSC V, R, and i filters are shown with grey dashed lines.