Spectrum of Gl 205 around the Ca II K line. The thin black and bold gray lines respectively represent the observed spectrum and a BT-Settl theoretical spectrum with T_eff = 3800 [K], log (g [cm/s] ) = 4.5, and Fe/H = 0.0. The dotted curve depicts the K filter. The bold black line represents part of the spectral contribution through the triangular K filter used to estimate the photospheric contribution in a previous study (Hartmann et al. 1984).