Broad-band SED at 50 ks after trigger. The observed data are represented by black filled circles. The HK_s bands provide only 3σ upper limits shown as arrows. The thick grey line shows the best-fit model able to reproduce the data: extinguished power law plus blackbody components, which are shown individually with dotted and dashed grey lines, respectively. The thin continuous grey lines show the unextinguished versions of the power law corresponding to the afterglow and the thermal component. In the lower panel, the residuals of the best fit are plotted.