Single-component blackbodies (optically thick case, dotted lines) and two-component analytic dust models (optically thin case, solid lines) compared to the MIR SEDs. At the first epoch, we eliminated the 4.5 μm point from the fitting, because of the excess flux from the 1 − 0 vibrational band of CO (see text for details). The IRS PUI fluxes are also shown as empty circles for illustration, but those were not included in the fitting.