Possible luminosities of brown dwarf 2MASS J1237+6526 (red triangles) compared with theoretically derived auroral luminosities (orange circles). Auroral luminosities are scaled after Jupiter and are calculated with L_Jupiter S_pot,rel Q_rel (= 1) (see text for details). The derived luminosities need to be considered with caution, but can be considered upper limits in any case, which is indicated symbolically as downward arrows.