Example of spectral typing via spectral comparison. The GMOS spectrum, normalised by the flux at 7050 Å, is shown in black in the regions used to calculated G and in grey elsewhere. The pair A_V = 0.75 mag, and M2-type stellar spectrum (green line) represents the best fit to the object. For comparison, spectra of M-1 and M-3 type stars are shown in blue and orange, respectively. The bottom panel shows the residuals of the comparison between the GMOS object and the M2-type stellar spectrum.