Illustration for a case of misclassification. The target is a reddening-free dwarf star with an effective temperature corresponding to a M2V spectral type. Its magnitudes are plotted as red dots with error bars. The best fit given by the FOSC is a K1IV spectral type with E_B−V = 0.70. The corresponding spectrum is plotted in a solid black line. The computed the flux in the bands of the filters is shown as black dots. The black box width gives the bandwidth of the corresponding filter. The same quantities are shown in blue for the correct spectrum.