2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/5201We review the orbital dynamics exhibited by the first extra-solar planetary system discovered, Upsilon Andromedae. This system is unique in combining all of the surprising architectural features displayed individually by extrasolar planetary systems found today: (1) a hot Jupiter, (2) two planets on highly eccentric orbits, and (3) a stellar companion. We discuss the system's stability properties and its possible origin. Planet-disk interactions seem critical to the emerging story.to appear in ASP Conference Series: Scientific Frontiers in Research on Extrasolar PlanetsAstrophysicstext