SED models for IRC +10 216, using Ṁ_dust = 4.0 × 10^-8 M_⊙ yr^-1, and the dust composition and properties listed in Table 3 and spatial distribution and properties shown in Fig. 4. The SED model is constrained by the ISO SWS and LWS data (full black); photometric points (black diamonds) are taken from Ramstedt et al. (2008) and Ladjal et al. (2010). Dash-dotted grey: model at maximum light, with 15 800 L_⊙, dashed grey: best fit to the ISO data, at phase ϕ = 0.24, using 11 300 L_⊙, dash-triple-dotted grey: model at minimum light, with 6250 L_⊙. The inset is identical, but plotted in log −log  scale.