论文标题
活跃的小行星331p/gibbs中的片段动力学
Fragment Dynamics in Active Asteroid 331P/Gibbs
论文作者
论文摘要
我们对碎片活跃的小行星331p/gibbs进行了动态分析。使用从2015年到2018年的哈勃太空望远镜拍摄的档案图像，我们测量了主要和三个最亮（大概是最大）组件的天体。常规的轨道测定显示组件之间的轨道相似性很高。然后，我们应用了一个碎片模型来拟合天文标准，获取包括碎片时期和分离速度在内的关键参数。我们的最佳拟合模型表明，片段B与初级身体分开，$ \ sim $ 1 cm s $ s $^{ - 1} $在2011年4月至5月之间，而两个可行的场景在片段A中确定了片段A和C。 2011年或2013年末至2014年初之间，以$ \ sim $ 0.7-0.8 cm s $^{ - 1} $的速度。结果与旋转破坏是导致小行星级联碎片的机制一致的，这是由初级旋转的快速旋转所暗示的。这些碎片构成了最年轻的已知小行星簇，为我们提供了研究小行星碎片化和小行星簇的形成的绝佳机会。
We present a dynamical analysis of the fragmented active asteroid 331P/Gibbs. Using archival images taken by the Hubble Space Telescope from 2015 to 2018, we measured the astrometry of the primary and the three brightest (presumably the largest) components. Conventional orbit determination revealed a high-degree of orbital similarity between the components. We then applied a fragmentation model to fit the astrometry, obtaining key parameters including the fragmentation epochs and separation velocities. Our best-fit models show that Fragment B separated from the primary body at a speed of $\sim$1 cm s$^{-1}$ between 2011 April and May, whereas two plausible scenarios were identified for Fragments A and C. The former split either from the primary or from Fragment B, in 2011 mid-June at a speed of $\sim$8 cm s$^{-1}$, and the latter split from Fragment B either in late 2011 or between late 2013 and early 2014, at a speed of $\sim$0.7-0.8 cm s$^{-1}$. The results are consistent with rotational disruption as the mechanism causing the cascading fragmentation of the asteroid, as suggested by the rapid rotation of the primary. The fragments constitute the youngest known asteroid cluster, providing us with a great opportunity to study asteroid fragmentation and formation of asteroid clusters.
