Estimated centrifugal radius of each mass shell. Beyond ≈ 10 AU, the centrifugal radius increases linearly. The solid line is the current centrifugal radius, while the dotted line is an estimate of r_cf after the expansion wave has passed and the associated magnetic braking has reduced the specific angular momentum (see text). The top axis shows the approximate times at which the expansion wave is expected to pass a certain radius. The symbols show the estimated centrifugal radii of 1 AU and 10 AU. The associated times are 6 × 10³ yr and 4 × 10⁴ yr.