Comparison between the S₁ ← S₀ origin band of anthracene measured in our laboratory (plotted as dotted blue curve), Staicu et al. (2004) and the UVES spectra obtained toward our programme stars. Red continuous lines represent synthetic stellar spectra obtained from the models of Gummersbach & Kauffer (1993). All stellar spectra have been rebinned to a wavelength frame where the detected interstellar absorption lines occur at an average radial velocity of 0 km s^-1, compared with the respective rest wavelengths in air.