Long‐Term Stability of the Ups And Planetary System Available to Purchase

Since the announcement of the triple planet system orbiting Upsilon Andromedae by Butler et al. in 1999 the best‐fit orbital parameters of the system have varied significantly with additional observations over the years. We have performed long‐term numerical integrations and a new stability analysis using the most recent best‐fit orbital parameters. All of our integrations run for a minimum of 10⁸ years, unless a close encounter between two planets or the collision of one planet with the central star occurs first. We vary systematically the value of the unknown inclination angle with respect to the plane of the sky as well as the relative inclinations. Based on these numerical results we are able to provide improved constraints on angles of inclination and the masses of the planets. We also find evidence against the claim that the middle and outer planets exhibit a secular resonance.