Continuum-normalized flux spectra toward HD 183143 (black line) and β Ori (gray line). The spectrum toward β Ori (European Southern Observatory) is vertically offset and its wavelength scale is corrected for convenient comparison. The vertical dotted line indicates the position of the A₀ band of C₆₀ at 4024 Å. Straight lines point to He I lines identified by their laboratory rest wavelengths (Kramida et al. 2021).