Megno map for the HD 31527 system, as obtained from the numerical integration of a grid of 300 × 300 initial conditions in the (a₃, e₃) plane. All other orbital elements were set to the nominal values. Integration time was set to 10⁴ yr, and escapes during this time span are highlighted in red. The color code shows values of (⟨Y ⟩ − 2). Dark blue corresponds to more regular orbits, and lighter tones of green indicate increasingly chaotic motion. The location of the outer planet is shown with a filled yellow circle, and the collision curve is plotted in gray. The libration widths of the most relevant MMRs determined analytically are plotted as white lines. See text for details.