发表机构
California Institute of Technology; University of Michigan（加州理工学院; 密歇根大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究揭示太阳质量损失的非平滑性（离散抛射）会引发外太阳系轨道随机游走，使其动力学寿命从10^18年骤降至约十亿年，数值实验显示多数系统在红巨星阶段即遭破坏。
AI 中文摘要
自诞生之初，天体力学就与太阳系动力学稳定性问题紧密交织。对于内行星而言，这一问题在统计上已得到解决：在水星离开主序带之前，其轨道有约1%的概率失稳。外太阳系看似更为安全，其固有动力学寿命估计约为10^18年。即使考虑到太阳质量损失和恒星飞掠，巨行星的轨道结构预计也能维持约100 Gyr。在此我们表明，这些估计基于太阳质量损失是平滑的这一假设。最近测量到的白矮星反冲要求存在不对称的质量损失，这种损失最可能归因于离散的、独立定向的抛射，它们以脉冲方式扰动恒星运动。当太阳以这种团块方式脱落其包层时，行星的轨道会以质量损失粒度为振幅进行随机游走。在观测允许的踢动所对应的粗糙度下，这种随机强迫在太阳死亡的同时重构了外太阳系。特别是，我们的数值实验揭示，轨道交叉可能在红巨星分支上开始，约40%的实现在白矮星形成前经历瓦解或剧烈散射，约90%在3 Gyr内自我毁灭。因此，外太阳系的动力学寿命从10^18年骤降至白矮星形成后约十亿年。
英文摘要
From its birth, celestial mechanics has been deeply intertwined with the question of the Solar System's dynamical stability. For the inner planets, this question is now statistically settled: Mercury's orbit carries a $\sim$1% chance of destabilization before the Sun leaves the main sequence. The outer Solar System has seemed more secure, with its intrinsic dynamical lifetime estimated at $\sim10^{18}$ years. Even accounting for the Sun's mass loss and stellar flybys, the orbital architecture of the giant planets had been expected to persist for $\sim$100 Gyr. Here we show that these estimates rest on the assumption that solar mass loss is smooth. The recently measured white dwarf recoil demands asymmetric mass loss that is most readily attributed to discrete, independently directed ejections that impulsively perturb stellar motion. As the Sun sheds its envelope in such parcels, the planets' orbits random-walk with amplitude set by the mass-loss granularity. At a coarseness corresponding to observationally permitted kicks, this stochastic forcing restructures the outer Solar System concurrently with the Sun's death. In particular, our numerical experiments reveal that orbit crossings can commence on the red giant branch, with $\sim$40% of realizations undergoing disruption or violent scattering before the white dwarf forms and $\sim$90% self-destructing within 3 Gyr. The outer Solar System's dynamical lifetime thus collapses from $10^{18}$ years to approximately a gigayear after white dwarf formation.
Comments13 pages, 7 figures, accepted for publication in ApJL
