Habitable zones for Earth-mass planets inmultiple planetary systems

摘要

We perform numerical simulations to study the Habitable zones (HZs) and dynamicalstructure for Earth-mass planets in multiple planetary systems. For example, in the HD 69830system, we extensively explore the planetary configuration of three Neptune-mass companionswith one massive terrestrial planet residing in 0.07 AU ≤ a≤1.20 AU, to examine the asteroidstructure in this system. We underline that there are stable zones of at least 105 yr for low-massterrestrial planets locating between 0.3 and 0.5 AU, and 0.8 and 1.2 AU with final eccentricitiesof e < 0.20. Moreover, we also find that the accumulation or depletion of the asteroid belt arealso shaped by orbital resonances of the outer planets, for example, the asteroidal gaps at 2:1and 3:2 mean motion resonances (MMRs) with Planet C, and 5:2 and 1:2 MMRs with Planet D.In a dynamical sense, the proper candidate regions for the existence of the potential terrestrialplanets or HZs are 0.35 AU < a < 0.50 AU, and 0.80 AU < a < 1.00 AU for relatively loweccentricities, which makes sense to have the possible asteroidal structure in this system.