Kuiper带天体的轨道动力学  

Orbit Dynamics of the Kuiper Belt Objects

作　　者：万晓生[1] 黄天衣[1] 

机构地区：[1]南京大学天文学系,南京210093

出　　处：《天文学进展》2002年第4期360-370,共11页Progress In Astronomy

基　　金：国家自然科学基金(10173007)

摘　　要：主要评述太阳系动力学研究的一个新方向——Kuiper带的轨道动力学。早期的研究是为了探讨短周期彗星的起源。在发现第一颗Kuiper带小天体之后,人们开始将注意力转到Kuiper带共振区的相空间结构上。Morbidelli和Malhotra分别采用不同的模型研究了这些共振区的大小,其中主要研究对象是3:2共振区。冥王星也处在这一共振区中。从冥王星的轨道特性来看,冥王星应是一颗较大的Kuiper带天体,它还拥有另外两种共振——Kozai共振和1:1超级共振。正是由于这些共振的存在,冥王星的运动才得以长期保持稳定。观测表明许多Kuiper带天体也处在海王星的平运动共振中。早期的理论认为这些平运动共振起源于灾难性事件,如碰撞。然而这都是一些小概率事件,无法对共振的形成进行合理的解释。Malhotra通过行星迁移成功地解释了冥王星被共振俘获的机制。这一机制的概率非常大,同样可以用来解释Kuiper带天体共振的形成。A new subject of the solar system dynamics, the orbit dynamics of the Kuiper Belt Objects, is reviewed in this paper. Early Studies were connected with the origin of short-period comets. After the first Kuiper Belt Object (KBO) was found, attentions are turned on the phase space structure of the resonant KBOs. Morbidelli and Malhotra adopted different model to study the sizes of the resonance regions, espically the 3:2 mean motion resonance which Pluto is in. For its obrital characters, Pluto should be called a large KBO. There are other two resonances in its motion, the Kozai resonance and 1:1 super resonance. It is because of these resonances that Pluto keeps its obrital stability. Observations show that lots of KBOs are in mean motion resonances with Neptune. In some early theories, these resonacnes were thought to be caused by catasrophic events such as collision, which can not explain the resonances well for their small probability. Malhotra proposed that Pluto was swept into the 3:2 resonance by planets migration, which happened very easily in the early stage of the solar system. This theory can also explain the resonance formation of KBO successfully.

关 键 词：轨道动力学 KUIPER带 共振 行星迁移 

分 类 号：P134[天文地球—天体力学]