显示极小减速的流星体的动态轨迹分析
Dynamic Trajectory Analysis of Meteoroids Showing Minimal Deceleration
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中文总结 AI 辅助
针对传统方法无法可靠分析极小减速天体（MDOs）的问题，提出基于仪器观测陨石及大型流星群的消融系数的新方法，分析全球火球观测台（GFO）2014-2024年约三分之一的MDOs，明确其特征并拓展了流星体动态分析范围。
中文摘要 AI 辅助
流星体在穿过大气层下降时会减速并消融，但部分仪器观测到的流星几乎没有可测量的减速，其特征仍知之甚少，这类天体被称为极小减速天体（MDOs）。传统的动态轨迹分析α-β法无法可靠确定它们的大气前质量或消融率。我们提出一种新方法，用于估计MDOs的弹道系数（α）和质量损失参数（β），使其可纳入动态分析。该方法采用从仪器观测到的陨石坠落及大型流星群天体中推导的整体消融系数，应用于约占全球火球观测台（GFO）2014-2024年数据集三分之一的MDOs。结果显示，MDOs主要是小型天体，占据α-β空间的独特区域；利用发射光谱等补充数据可识别其物质类型，我们通过10个小型铁流星体的观测证明了这一点。该方法扩大了动态轨迹分析可研究的流星体群体范围，为陨石沉积及近地天体的成分多样性提供了新约束。
英文摘要
Meteoroids decelerate and ablate as they descend through the atmosphere, however a portion of instrumentally observed meteors show little measurable deceleration and remain poorly characterised. These are referred to as minimally decelerating objects (MDOs). The traditional alpha-beta method of dynamic trajectory analysis cannot reliably determine their preatmospheric masses or rates of ablation. We present a new approach for estimating the ballistic coefficients (alpha) and mass loss parameters (beta) of MDOs, allowing their inclusion in dynamic analyses. This new method employs bulk ablation coefficients derived from instrumentally observed meteorite falls and large meteor shower bodies. It is applied to MDOs comprising approximately one-third of the Global Fireball Observatory (GFO) 2014 - 2024 dataset. Our results show that MDOs are predominantly small objects occupying a distinct region of alpha-beta space. Material types can be identified using supplementary data such as emission spectra, which we demonstrate using observations of 10 small iron meteoroids. This methodology expands the range of meteoroid populations accessible to dynamic trajectory analysis, providing new constraints on meteorite deposition and the compositional diversity of near-Earth objects.
