First trans-Neptunian object in polar resonance with Neptune
First trans-Neptunian object in polar resonance with Neptune
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DOI：
10.1093/mnrasl/slx125
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发表时间：
2017-08
影响因子：
4.8
通讯作者：
M. Morais;F. Namouni
中科院分区：
文献类型：
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作者：
M. Morais;F. Namouni
在太阳系中，对于具有中等倾角的逆轨道和逆行轨道的小物体，观测到了在平均运动共振中的捕获。然而，没有一个接近极地轨道的物体与行星共振的例子。在这封信中，我们报告说，近极地的穿海王星天体（471325），绰号为Niku，与海王星处于7：9的共振状态，共振状态下的平均寿命为1600万+-1100万年。虽然7：9共振的进入和退出是由与海王星的近距离接触引起的，但共振配置提供了一个临时的保护机制，防止与这颗行星的破坏性近距离接触。其他接近极地的穿海王星天体似乎与行星没有共振，可能除了2008 KV 42，也被称为Drac，它与海王星有8：13共振的可能性很小。
Capture in mean motion resonance has been observed in the Solar System for small objects with prograde as well as retrograde orbits of moderate inclinations. However, no example of an object with a nearly polar orbit was known to be in resonance with a planet. In this Letter, we report that the nearly-polar transneptunian object (471325), nicknamed Niku, is in a 7:9 resonance with Neptune, with a mean lifetime in resonance of 16 +- 11 million years. While entrance and exit in the 7:9 resonance is caused by close encounters with Neptune the resonant configuration provides a temporary protection mechanism against disruptive close encounters with this planet. The other nearly polar transneptunian objects do not seem to be in resonance with the planets with the possible exception of 2008 KV42, also known as Drac, that has a small chance of being in the 8:13 resonance with Neptune.