Normalized SINFONI H-band (left) and K-band (right) spectra of the first 21 objects. For most of these objects we were able to derive the spectral type (Table 2). The location of some of the absorption lines used for the classification of the stars are shown by the vertical dashed lines. The combination of Mg i , Na i and Ca i absorption lines proved to be the best temperature tracers. The width of the CO lines in the K-band gives an indication of the luminosity class.