Megno map for a circumbinary system in the (a, e) plane. The color code shows values of Y^* = log₁₀(⟨Y ⟩− 2). Dark blue corresponds to more regular orbits, and lighter tones of green indicate increasingly chaotic motion. The libration widths of the most relevant MMRs determined with the model are plotted as white lines, setting ϖ = 180^o. The top scale indicates the positions of N∕1 resonances with respect to the mean motion of the binary. See text for details.