Mass-luminosity diagram with the components of LHS 1070, the models of Baraffe et al. (1998), and the empirical Mass-Luminosity-Relation by Henry et al. (1999). Shown are the theoretical isochrones for ages between 500 Myr and 5 Gyr. The dotted horizontal line indicates the mass range for A resulting from stable orbit configurations. The points labeled “Aa photometry” and ”D photometry” indicate the magnitudes if A is split into two components (Henry et al. 1999), with the masses adjusted to put the points onto the 630-Myr isochrone.