Scheeres D J, McMahon J W, Brack D N, French A S, Chesley S R, Farnocchia D, Vokrouhlický D, Ballouz R-L, Emery J P, Rozitis B, Nolan M C, Hergenrother C W, Lauretta D S
Smead Department of Aerospace Engineering Sciences University of Colorado Boulder Boulder CO USA.
Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA.
J Geophys Res Planets. 2020 Mar;125(3):e2019JE006284. doi: 10.1029/2019JE006284. Epub 2020 Mar 11.
This paper explores the implications of the observed Bennu particle ejection events for that asteroid's spin rate and orbit evolution, which could complicate interpretation of the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) and Yarkovsky effects on this body's spin rate and orbital evolution. Based on current estimates of particle ejection rates, we find that the overall contribution to Bennu's spin and orbital drift is small or negligible as compared to the Yarkovsky and YORP effects. However, if there is a large unseen component of smaller mass ejections or a strong directionality in the ejection events, it could constitute a significant contribution that could mask the overall YORP effect. This means that the YORP effect may be stronger than currently assumed. The analysis is generalized so that the particle ejection effect can be assessed for other bodies that may be subject to similar mass loss events. Further, our model can be modified to address different potential mechanisms of particle ejection, which are a topic of ongoing study.
本文探讨了观测到的贝努小行星粒子喷射事件对该小行星自转速率和轨道演化的影响，这可能会使对雅科夫斯基 - 奥基夫 - 拉季耶夫斯基 - 帕达克（YORP）效应以及雅科夫斯基效应在该天体自转速率和轨道演化方面的解释变得复杂。基于目前对粒子喷射速率的估计，我们发现，与雅科夫斯基效应和YORP效应相比，粒子喷射对贝努小行星自转和轨道漂移的总体贡献很小或可忽略不计。然而，如果存在大量未被观测到的小质量粒子喷射成分，或者喷射事件具有很强的方向性，那么这可能构成显著贡献，从而掩盖整体的YORP效应。这意味着YORP效应可能比目前所假设的更强。该分析具有普遍性，以便可以评估其他可能经历类似质量损失事件的天体的粒子喷射效应。此外，我们的模型可以进行修改，以探讨粒子喷射的不同潜在机制，这是当前正在研究的一个课题。
