Extinction curve normalized by the visible extinction A _λ /A _V on the LOS toward the central star, Betelgeuse (z = 0 R _*, left panel), and toward a background star (z = 5000 R _*, right panel). The original dust with ﹩{a}_{\max }=0.5\,\mu {\rm{m}}﹩ and η = 0.002 is adopted. Compared with the case of no dust disruption (dashed–dotted black line), the RAT-D effect results in a decrease in optical–IR extinction and an increase in far-UV extinction produced by porous grains (lower ﹩{S}_{\max }﹩).