The effect of aspect changes on Near-Earth Asteroid phase curves
The effect of aspect changes on Near-Earth Asteroid phase curves
复制标题
方位变化对近地小行星相位曲线的影响
DOI：
10.1093/mnras/stac1053
复制
发表时间：
2022
影响因子：
4.8
通讯作者：
Jackson S
中科院分区：
文献类型：
--
作者：
Jackson S
小行星的相位曲线通常被认为只取决于无空气微粒表面的散射特性和被研究物体的大小。在这项研究中，我们证明了额外的依赖对象的形状，旋转极的方向，和观看的几何形状的幻影的相位曲线。通过对近地小行星（159402）1999 AP 10在2020年7月至2021年1月期间出现的相位曲线的分析，证实其相位曲线的变化是由于出现时的方位角变化引起的。这是通过对小行星的形状建模和模拟幻影上的相位曲线来实现的。我们提出了一系列的几何形状的小行星相位曲线的模拟，以了解这方面的影响的潜在幅度，在这种情况下，它可以开始占主导地位的相位曲线。这种对方位的依赖性可能会在从相位曲线数据导出的性质中引入显著的额外不确定性。我们提供并演示了软件代码，通过模拟和模型拟合随机生成的样本椭球形小行星模型在观察到的几何形状来估计近地小行星相位曲线的方面相关的不确定性。我们演示了如何忽略这种影响可能会导致误导性的解释的数据和低估的不确定性，在进一步的研究中，如在红外线，使用相位曲线导出的参数时，拟合的小行星的物理特性。
Phase curves of asteroids are typically considered to depend solely on the scattering properties of airless particulate surfaces and the size of the object being studied. In this study, we demonstrate the additional dependence of phase curves on object shape, rotation pole orientation, and viewing geometry over an apparition. Variations in the phase curve of near-Earth asteroid (159402) 1999 AP10 over its apparition from 2020 July to 2021 January are verified to be due to aspect changes over the apparition. This is achieved through shape modelling of the asteroid and simulation of the phase curve over the apparition. We present simulations of asteroid phase curves over a range of geometries to understand the potential magnitude of this aspect effect, and under which circumstances it can begin to dominate in the phase curves. This dependence on aspect may introduce significant additional uncertainty in the properties derived from phase-curve data. We provide and demonstrate software code to estimate the aspect-related uncertainty in near-Earth asteroid phase curves through simulation and model fitting of a randomly generated sample of ellipsoidal asteroid models over the observed viewing geometry. We demonstrate how ignoring this effect may lead to misleading interpretations of the data and underestimation of uncertainties in further studies, such as those in the infrared that use phase curve derived parameters when fitting physical properties of an asteroid.