Orbital resonance in a dissipative medium
Orbital resonance in a dissipative medium
复制标题
耗散介质中的轨道共振
DOI：
10.1016/0019-1035(78)90024-6
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发表时间：
1978
期刊：
影响因子：
3.2
通讯作者：
R. Greenberg
中科院分区：
文献类型：
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作者：
R. Greenberg
轨道共振往往迫使物体进入非圆形轨道。如果一个物体也受到一种减小偏心率的介质的影响，它将经历半长轴的长期变化，这种变化可能是正的，也可能是负的，这取决于它的轨道是在扰动物体的轨道的外部还是内部。因此，耗散介质可以促进轨道能量的损失或增益。这个过程可以解释小行星带和土星环的共振结构。对于合理的早期太阳系参数，它将在几千年的时间尺度上在与木星的2：1共振附近清除一个间隙;差距宽度将与小行星带目前位置的柯克伍德间隙相当。同样地，在20106年土星环与土卫一的2：1共振时，一个宽度与卡西尼号相当的间隙将被清除。来自差距的大部分材料将沉积在环B的外边缘处。这个过程也会影响行星前物质的径向分布。此外，它提供了一个解释的大振幅的钛-天平动。考虑耗散对限制性三体问题稳定L4和L5点附近轨道的影响表明，能量损失导致粒子远离这些点。这一结果解释了特洛伊小行星在这些点附近的大振幅以及特洛伊小行星可能被捕获到木星轨道上的原因。
Orbital resonances tend to force bodies into noncircular orbits. If a body is also under the influence of an eccentricity-reducing medium, it will experience a secular change in semimajor axis which may be positive or negative depending on whether its orbit is exterior or interior to that of the perturbing body. Thus a dissipative medium can promote either a loss or a gain in orbital energy. This process may explain the resonant structure of the asteroid belt and of Saturn's rings. For reasonable early solar system parameters, it would clear a gap near the 2:1 resonance with Jupiter on a time scale of a few thousand years; the gap width would be comparable to the Kirkwood gap presently at the location in the asteroid belt. Similarly, a gap comparable in width to Cassini's division would be cleared in Saturn's rings at the 2:1 resonance with Mimas in ∼106yr. Most of the material from the gap would be deposited at the outer edge of ring B. The process would also affect the radial distribution of preplanetary material. Moreover, it provides an explanation for the large amplitude of the Titan-Hyperion libration. Consideration of the effects of dissipation on orbits near the stable L4and L5points of the restricted three-body problem indicates that energy loss causes particles to move away from these points. This results explains the large amplitude of Trojan asteroids about these points and the possible capture of Trojan into orbit about Jupiter.