Left: SED. The solid grey line shows the combination of a 12 000 K black body (dot-dashed line) with the photosphere model (dashed line, see Sect. 3.1). The dotted black line and the grey shadowed region trace the median SED and upper/lower quartiles of Class II discs around K2-M5 stars in Taurus (Furlan et al. 2006). The dotted grey line shows the power-law fit F_ν ∝ ν^α, with α = 2.5 ± 0.1 (see Sect. 3.2). Top right: IRS/Spitzer spectra. The light blue rectangle is centred around the 33.8 μm crystalline silicate feature, and the grey shadowed region indicates the spectra uncertainties. Bottom right: de-redened and normalized 10 μm profile of DZ Cha and GM Aur.