PLANETARY SPIN-AXIS EVOLUTION IN THE 47 UMa HABITABLE ZONE

摘要

The long-term secular perturbations between planets in a planetary system affect their individual obliquities and precession rates. This spin-axis evolution has been numerically investigated for hypothetical Earth-like planets located in and further inward of the habitable zone of the 47 UMa planetary system. If was found that the spin-axis for such a planet can undergo relatively large variations (up to 40°) on short time scales (10~4-10~5 yr). Such variations are expected to have profound implications for the long-term atmosphere and surface conditions of a planet and put further constraints on the potential habitability in the 47 UMa system.