We present results of modelling the bulk of the spectral energy distribution ( 0.35 - 5 \mu m ) for GJ406 ( M6V ) .
Synthetic spectra were calculated using the NextGen Dusty and Cond model atmospheres and incorporate line lists for H _ { 2 } O , TiO , CrH , FeH , CO , MgH molecules as well as the VALD line list of atomic lines .
A comparison of synthetic and observed spectra gives T _ { eff } ~ { } = 2800 \pm 100 K. We determine M _ { bol } = 12.13 \pm 0.10 for which evolutionary models by Baraffe et al .
( 2003 ) suggest an age of around 0.1 – 0.35 Gyr consistent with its high activity .
The age and luminosity of GJ406 correspond to a wide range of plausible masses ( 0.07 – 0.1 M _ { \odot } ) .