Left: mid-infrared SEDs for α Cen A for different values of the power-law exponent q of the size distribution function, viz. n(a) ∝ a^− q. Black curves depict dust SEDs, whereas blue curves display the total, i.e. . For each q, there are graphs for a selection of initial dust mass estimates and the fractional dust luminosity, f_d = L_dust/L_star, is shown next to each curve. The 100 μm data were not part of the fitting procedure. Right: same as the left panel but for α Cen B and with the total emission shown in red.