Emission feature in the spectra of DG Tau. Dashed and solid blue lines show the continuum subtracted uncorrelated spectra of DG Tau in two epochs. Dashed and solid gray lines show the continuum subtracted spectra measured by Spitzer in 2005 October 9 and 2006 March 17, respectively (Bary et al. 2009), corrected for an average absorption (see text for details). The red line represents the emission feature in the spectrum of comet Hale-Bopp, scaled to match the solid blue curve.