海王星特洛伊:回顾与新成员
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摘要
目前观测到的海王星特洛伊天体已有17颗并已积累了较为精确的轨道数据,系统分析了这些天体轨道的动力学稳定性.数值结果表明:除去两个寿命短到只有数万年和百万年的临时海王星特洛伊,大部分天体在其轨道根数不确定范围内都可以存活至45亿年.大约有一半的海王星特洛伊在45亿年的时间内离开共振区,而逃离的途径是复杂动力学机制下轨道根数空间内缓慢的扩散.在半人马小行星群中识别并证认了一个新的海王星特洛伊天体2012 UW177,数值模拟表明该天体目前正在围绕海王星L4点的蝌蚪形轨道上运动.该天体大约在23万年前进入当前轨道,且未来将在该轨道停留至少130万年.约54°的倾角使得它的轨道成为最倾斜的轨道,并且使得该天体展现经由拟卫星轨道的复杂有趣的共轨轨道转换.
Up to now, 17 Neptune Trojan asteroids have been detected with their orbits being well determined by continuous observations. This paper revisits their orbital dynamics. Except for two temporary members with relatively short lifespans on trojan orbits, our results show that the vast majority of Neptune Trojans located within their orbital uncertainties may survive in the Solar system age. The escaping probability of Neptune Trojans, through slow diffusion in the orbital element space in 4.5 billion years, is estimated to be ~50%. In our survey in the data of asteroids in the vicinity of Neptune's orbit, we identify 2012 UW177 as a new Neptune Trojan.Numerical simulations indicate that it is librating on tadpole orbit around Neptune's L4 point. It was captured into current orbit approximately 0.23 million years ago, and will stay there for at least another 1.3 million years in the future. Its high inclination i ≈ 54° not only makes it the most inclined Neptune Trojan, but also makes the interesting co-orbital transitions possible between the leading and trailing trojans via the quasi-satellite orbit phase.
Up to now, 17 Neptune Trojan asteroids have been detected with their orbits being well determined by continuous observations. This paper revisits their orbital dynamics. Except for two temporary members with relatively short lifespans on trojan orbits, our results show that the vast majority of Neptune Trojans located within their orbital uncertainties may survive in the Solar system age. The escaping probability of Neptune Trojans, through slow diffusion in the orbital element space in 4.5 billion years, is estimated to be ~50%. In our survey in the data of asteroids in the vicinity of Neptune's orbit, we identify 2012 UW177 as a new Neptune Trojan.Numerical simulations indicate that it is librating on tadpole orbit around Neptune's L4 point. It was captured into current orbit approximately 0.23 million years ago, and will stay there for at least another 1.3 million years in the future. Its high inclination i ≈ 54° not only makes it the most inclined Neptune Trojan, but also makes the interesting co-orbital transitions possible between the leading and trailing trojans via the quasi-satellite orbit phase.
引文
[1]Alexandersen M,Gladman B,Greenstreet S,et al.Science,2013,341:994
[2]Connors M,Wiegert P,Veillet C.Nature,2011,475:481
[3]Chiang E I,Jordan A B,Millis R L,et al.AJ,2003,126:430
[4]Brasser R,Mikkola S,Huang T Y,et al.MNRAS,2004,347:833
[5]Horner J,Lykawka P S.MNRAS,2010,405:49
[6]Sheppard S S,Trujillo C A.Science,2010,329:1304
[7]Mikkola S,Innanen K.AJ,1992,104:1641
[8]Holman M J,Wisdom J.AJ,1993,105:1987
[9]Nesvorny′D,Dones L.Icarus,2002,160:271
[10]Marzari F,Tricarico P,Scholl H.A&A,2003,410:725
[11]Dvorak R,Schwarz R,Su¨liA′,et al.MNRAS,2007,382:1324
[12]Zhou L Y,Dvorak R,Sun Y S.MNRAS,2009,398:1217
[13]Zhou L Y,Dvorak R,Sun Y S.MNRAS,2011,410:1849
[14]Chiang E I,Lithwick Y.Ap J,2005,628:520
[15]Sheppard S S,Trujillo C A.Science,2006,313:511
[16]Parker A H,Buie M W,Osip D J,et al.AJ,2013,145:96
[17]Lin H W,Chen Y T,Holman M J,et al.AJ,2016,152:147
[18]Gerdes D W,Jennings R J,Bernstein G M,et al.AJ,2016,151:39
[19]Chambers J E.MNRAS,1999,304:793
[20]Guan P,Zhou L Y,Li J.RAA,2012,12:1549
[21]Horner J,Lykawka P S.MNRAS,2012,426:159
[22]Dong C Y,Zhou L Y,Cui J.2018,submitted
[23]Alexandersen M,Gladman B,Kavelaars J J,et al.AJ,2016,152:111
[24]Murray C D,Dermott S F.Solar System Dynamics.Cambridge:Cambridge University Press,1999:316
[25]Namouni F.Icarus,1999,137:293
[26]Namouni F,Christou A A,Murray C D.Ph Rv L,1999,83:2506
1http://www.minorplanetcenter.net
2https://ssd.jpl.nasa.gov
3 http://hamilton.dm.unipi.it
[2]Connors M,Wiegert P,Veillet C.Nature,2011,475:481
[3]Chiang E I,Jordan A B,Millis R L,et al.AJ,2003,126:430
[4]Brasser R,Mikkola S,Huang T Y,et al.MNRAS,2004,347:833
[5]Horner J,Lykawka P S.MNRAS,2010,405:49
[6]Sheppard S S,Trujillo C A.Science,2010,329:1304
[7]Mikkola S,Innanen K.AJ,1992,104:1641
[8]Holman M J,Wisdom J.AJ,1993,105:1987
[9]Nesvorny′D,Dones L.Icarus,2002,160:271
[10]Marzari F,Tricarico P,Scholl H.A&A,2003,410:725
[11]Dvorak R,Schwarz R,Su¨liA′,et al.MNRAS,2007,382:1324
[12]Zhou L Y,Dvorak R,Sun Y S.MNRAS,2009,398:1217
[13]Zhou L Y,Dvorak R,Sun Y S.MNRAS,2011,410:1849
[14]Chiang E I,Lithwick Y.Ap J,2005,628:520
[15]Sheppard S S,Trujillo C A.Science,2006,313:511
[16]Parker A H,Buie M W,Osip D J,et al.AJ,2013,145:96
[17]Lin H W,Chen Y T,Holman M J,et al.AJ,2016,152:147
[18]Gerdes D W,Jennings R J,Bernstein G M,et al.AJ,2016,151:39
[19]Chambers J E.MNRAS,1999,304:793
[20]Guan P,Zhou L Y,Li J.RAA,2012,12:1549
[21]Horner J,Lykawka P S.MNRAS,2012,426:159
[22]Dong C Y,Zhou L Y,Cui J.2018,submitted
[23]Alexandersen M,Gladman B,Kavelaars J J,et al.AJ,2016,152:111
[24]Murray C D,Dermott S F.Solar System Dynamics.Cambridge:Cambridge University Press,1999:316
[25]Namouni F.Icarus,1999,137:293
[26]Namouni F,Christou A A,Murray C D.Ph Rv L,1999,83:2506
1http://www.minorplanetcenter.net
2https://ssd.jpl.nasa.gov
3 http://hamilton.dm.unipi.it