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arXiv 1805.04478astro-ph.EP
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1000颗偶然观测到的主带小行星的分类学和光变曲线数据

Taxonomy and Light-Curve Data of 1000 Serendipitously Observed Main-Belt Asteroids

N. Erasmus, A. McNeill, M. Mommert, D. E. Trilling, A. A. Sickafoose, C. van Gend

摘要:

我们提出了1003主带小行星(MBA)观察与萨瑟兰,南非,韩国微透镜望远镜网络(KMTNet)的节点VRI分光光度法。所有观察到的MBA都是在一项单独的近地小行星研究中偶然捕获的KMTNet的大型2度$\times$ 2度视场(Erasmus等人,2017年)。我们的宽带分光光度法是可靠的,足以区分四个小行星分类,我们有信心地分类836的1003个观测目标,无论是S-,C-,X-或D-型小行星的机器学习(ML)算法的方法。我们的数据表明,S型MBA和(C+X+D)型MBA之间的比例,与H级之间的12和18(12公里的$\gtrsim$直径$\gtrsim$ 0.75公里),几乎正好是1:1。此外,我们报告了每个MBA的0.5至3小时(中位数:1.3小时)的光变曲线数据,并解决了59个目标的完整旋转周期和振幅。59个目标中有两个的旋转周期可能低于理论上的零凝聚力边界限制2.2小时。我们报告的旋转周期和振幅的下限为其余的目标。使用解决和未解决的光变曲线,我们确定了这个人口的形状分布,使用蒙特卡罗模拟。我们的模型表明,人口的平均伸长率$b/a = 0.74\pm0.07$,也表明,这是独立的小行星的大小和分类。

英文摘要:

We present VRI spectrophotometry of 1003 Main-Belt Asteroids (MBAs) observed with the Sutherland, South Africa, node of the Korea Microlensing Telescope Network (KMTNet). All of the observed MBAs were serendipitously captured in KMTNet's large 2deg $\times$ 2deg field of view during a separate targeted near-Earth Asteroid study (Erasmus et al. 2017). Our broadband spectrophotometry is reliable enough to distinguish among four asteroid taxonomies and we confidently categorize 836 of the 1003 observed targets as either a S-, C-, X-, or D-type asteroid by means of a Machine Learning (ML) algorithm approach. Our data show that the ratio between S-type MBAs and (C+X+D)-type MBAs, with H magnitudes between 12 and 18 (12 km $\gtrsim$ diameter $\gtrsim$ 0.75 km), is almost exactly 1:1. Additionally, we report 0.5- to 3-hour (median: 1.3-hour) light-curve data for each MBA and we resolve the complete rotation periods and amplitudes for 59 targets. Two out of the 59 targets have rotation periods potentially below the theoretical zero cohesion boundary limit of 2.2 hours. We report lower limits for the rotation periods and amplitudes for the remaining targets. Using the resolved and unresolved light curves we determine the shape distribution for this population using a Monte Carlo simulation. Our model suggests a population with an average elongation $b/a = 0.74\pm0.07$ and also shows that this is independent of asteroid size and taxonomy.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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