Could the 47 Ursae Majoris Planetary System be a Second Solar System? Predicting the Earth‐like Planets

(Abridged)We numerically investigated the dynamical architecture of 47 UMawith the planetary configuration of the best-fit orbital solutions by Fischeret al. We systematically studied the existence of Earth-like planets in theregion 0.05 AU $\leq a \leq 2.0$ AU for 47 UMa with numerical simulations, andwe also explored the packed planetary geometry and Trojan planets in thesystem. In the simulations, we found that "hot Earths" at 0.05 AU $\leq a < $0.4 AU can dynamically survive at least for 1 Myr. The Earth-like planets caneventually remain in the system for 10 Myr in areas involved in the mean motionresonances (MMR) (e.g., 3:2 MMR) with the inner companion. Moreover, we showedthat the 2:1 and 3:1 resonances are on the fringe of stability, while the 5:2MMR is unstable. Additionally, the 2:1 MMR marks out a remarkable boundarybetween chaotic and regular motions, inside, most of the orbits can survive,outside, they are mostly lost in the orbital evolution. In a dynamical sense,the most likely candidate for habitable environment is Earth-like planets withorbits in the ranges 0.8 AU $\leq a < 1.0$ AU and 1.0 AU $ < a < 1.30$ AU(except several unstable cases) with relatively low eccentricities. The Trojanplanets with low eccentricities and inclinations can secularly last at thetriangular equilibrium points of two massive planets. Hence, the 47 UMaplanetary system may be a close analog to our solar system.Comment: 20 Pages, 4 figures, accepted for publication in ApJ, scheduled for 10 October 2005, v632, 1 issu