Close approaches of trans-Neptunian objects to Pluto have left observable signatures on their orbital distribution
Close approaches of trans-Neptunian objects to Pluto have left observable signatures on their orbital distribution
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DOI：
10.1086/301208
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发表时间：
2000-02-01
影响因子：
5.3
通讯作者：
Ferraz-Mello, S
中科院分区：
文献类型：
--
作者：
Nesvorny, D;Roig, F;Ferraz-Mello, S
结果表明，除了四个外行星（木星到海王星）冥王星也应考虑在跨海王星区域的轨道动力学研究。冥王星对2：3海王星平均运动共振轨道的影响特别大。当只考虑四颗外行星的引力作用时，在太阳系的年龄段内发现的稳定轨道经常在冥王星接近的影响下不稳定。我们估计，许多动态原始机构最初移动低到中等幅度的2：3海王星共振（半长轴39.45 Au）已被从各自的，否则稳定的位置，当他们的共振振幅增加的过程中，密切接触冥王星。在大的天平动振幅下，轨道变得混乱，物体从2：3共振中被弹射到海王星交叉轨道。共振振幅激发的过程对于中等倾角和大倾角（i > 8度）的轨道特别有效，在这种轨道上，在4 x 10（9）年内已经消除了50%以上的人口。我们估计，在这些倾角的原始共振人口的其余部分应该有其共振振幅激发到约80度。冥王星对低倾角轨道的影响较小。我们已经检查了在2：3共振轨道（Plutinos）上观测到的33个天体的分布，发现实际上可能存在上述机制的迹象。与随机产生的分布相比，冥王星的共振振幅异常高，为0.15 < e < 0.3，而且只有一个物体（1997 QJ 4）在与冥王星相似的轨道上。事实上，在冥王星的倾角和离心率上，冥王星的分布可能会出现一定的差距，如果未来的观测得到证实，这可能是冥王星横扫效应的结果。
It is shown that in addition to four outer planets (Jupiter to Neptune) Pluto should be also taken into account in studies of the orbital dynamics in the trans-Neptunian region. Pluto's effect is particularly large on the orbits in the 2:3 Neptune mean motion resonance. The trajectories found stable over the age of the solar system when only the gravitational effect of four outer planets is considered are often destabilized there in the effect of close Pluto approaches. We estimate that many dynamically primordial bodies moving initially with low to moderate amplitudes in the 2:3 Neptune resonance (semimajor axis 39.45 AU) have been removed from their respective, otherwise stable, locations, when their resonant amplitudes increased in the course of close encounters with Pluto. At large libration amplitude, the orbits became exposed to chaotic changes, and objects were ejected from the 2:3 resonance to Neptune-crossing trajectories. The process of the resonant amplitude excitation was especially efficient for orbits with moderate and large inclinations (i > 8 degrees), where more than 50% of the population has been removed in 4 x 10(9) yr. We estimate that the remaining part of the primordial resonant population at these inclinations should have had its resonant amplitude excited to about 80 degrees. The effect of Pluto on low-inclination orbits is smaller. We have examined the distribution of 33 objects observed on the 2:3 resonant orbits (Plutinos) and found that there could actually exist indications of the above mechanism. The resonant amplitudes of Plutinos are unusually high for 0.15 < e < 0.3 when compared with randomly generated distribution, and, also, there is only one object (1997 QJ4) on an orbit similar to that of Pluto. In fact, a certain gap may be noticed in the distribution of Plutinos at Pluto's inclination and eccentricity, which, if confirmed by future observations, may be the consequence of Pluto's sweeping effect.