We integrate the orbital solutions of the planets orbiting 55 Cancri. In the simulations, we find that not only do the three resonant arguments theta(1) = lambda(1) - 3lambda(2) + 2 (ω) over tilde (1), theta(2) = lambda(1) - 3lambda(2) + 2 (ω) over tilde (2), and theta(3) = lambda(1) - 3lambda(2) + ((ω) over tilde (1) + (ω) over tilde (2)) librate, respectively, but the relative apsidal longitude Deltaomega also librates about 250degrees for millions of years. The results imply the existence of the 3 : 1 resonance and the apsidal resonance for the studied system. We emphasize that the mean motion resonance and apsidal locking can act as two important mechanisms for stabilizing the system. In addition, we further investigate the secular dynamics of this system by comparing the numerical results with those given by Laplace-Lagrange secular theory.
1.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China 2.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 3.Natl Astron Observ Japan, Tokyo 1818588, Japan 4.Nanjing Univ, Dept Astron, Nanjing 210093, Jiangsu, Peoples R China