... DE 20 0 [103] determine the primary distance scale factor, the astronomical unit (AU). This unit is the most accu- rate astrometric parameter, with an estimated uncertainty of &50m (Standish, ... with time. This solution fits the mean motions of Jupiter-Saturn (.!?I = (2& amp;, - 5Ls) with the terrestrial planet orbits to ~25 ” or better, but achieves 883 yr. period) and Uranus-Neptune ... 24 513 02. 5 10.5 15.5 1.77 1 92. 80 20 9.90 6 .26 3 0.46357 3. 728 9 24 50667.6 5.5 13.0 359 .22 1 72. 52 194.68 31. 828 0.70649 3. 522 9 24 48 725 .7 9.0 15.5 2. 87 359 .27 21 2.63 21 .104 0.66433 2. 9633 24 48 825 .6...