Equivalent-width detection threshold in the 6000 Å region for seven LOSs (solid curves). The vertical dotted line shows the expected position of the γ₀ band of C₆₀ in all spectra. Positions of DIBs according to Hobbs et al. (2009) are indicated in the bottom panel (short vertical lines). The predicted position of a line of stellar Ne I is marked in each panel (arrow). In four cases detection limits were computed as fitted profiles of the DIBs nearest 6070 Å were included in the continuum (short-dashed curves). An unidentified absorption would cause the rise near 6078 Å (asterisk).