最近的多普勒观测表明恒星HD12661周围存在两颗中等偏心率轨道上运行的行星,内行星的最小质量为2.3木星质量,轨道周期为263.6天;外行星的最小质量为1.57木星质量,轨道周期为1444.5天.该系统的稳定性要求两颗行星处在平运动轨道共振.用数值方法研究了该系统形成初期在恒星气体盘作用下的轨道迁移与稳定性,计算了行星在迁移中被平运动共振俘获的概率.发现这两颗行星目前很可能正处在11:2平运动共振边缘,且运动是混沌的,从而澄清了关于系统目前构形的不同说法,并且很可能在系统形成后行星迁移到目前构形时,气体盘几乎消失了.
Recent Doppler velocity measurements have revealed the presence of two planets orbiting the star HD 12661 on medium eccentric orbits. The inner planet has a period of 263.6 days with of 2.3 times of Jupiter mass, while the outer planet has a period of 1444.5 days with of 1.57 times of Jupiter mass. Some types of resonances are required to keep the system stable. The stability and migration of the planets due to proto-stellar disk after the planets formed are explored, and the probabilities of a set of orbits captured in some resonances during migrations are calculated. The results indicate that the two planets of this system may be on the edge of the 11:2 resonance currently, and they are in chaotic motions. These results are helpful to understand whether the two planets of this system are in mean motion resonances and which resonance are they in.