UVES spectra covering the region where the strongest absorption peaks in the S_β ← S₀ transition of hexabenzocoronene are expected. The dashed blue curve represents the hexabenzocoronene spectrum as measured in an Ne matrix and shifted to the expected gas phase position following the method described in Sect. 2.2. The two narrow bands, plotted as dotted blue curve, are synthetic low-temperature gas phase profiles drawn at their predicted gas phase positions (see text). The sharp absorption feature at 3384 Å is due to interstellar Ti ii. See Fig. 4 for further details.