Video observations of tiny near-Earth objects with Tomo-e Gozen
Video observations of tiny near-Earth objects with Tomo-e Gozen
复制标题
使用 Tomo-e Gozen 对近地微小天体进行视频观测
DOI：
10.1093/pasj/psac043
复制
发表时间：
2022
影响因子：
2.3
通讯作者：
Ohsawa Ryou et al. (23 authors including Doi Mamoru)
中科院分区：
文献类型：
--
作者：
Beniyama Jin;Sako Shigeyuki;Ohsawa Ryou et al. (23 authors including Doi Mamoru)
我们报告用木曾105厘米施密特望远镜上的Tomo-e Gozen对微小（直径小于100米）近地天体进行视频观测的结果。小行星的自转周期反映了其动力学历史和物理特性，因为较小的天体对Yarkovsky-O 'Keefe-Radzievskii-Paddack（YORP）效应很敏感。我们在2018年至2021年期间以2 fps的速度对60个微小近地天体进行了视频观测，并成功地导出了32个近地天体的旋转周期和轴比，其中包括13个旋转周期小于60 s的快速旋转体。在我们的调查中发现的最快的旋转器是2020 HS，旋转周期为2.99秒。我们从统计数据上证实，近地天体群中有一定数量的微小快速自转体，这在以前的所有调查中都被遗漏了。我们发现，微小近地天体在直径和旋转周期图中的分布在10秒左右被截断。用近地天体的实际抗拉强度或流星体撞击抑制YORP都不能很好地解释平顶形状的截断。我们建议，旋转周期的切向YORP效应的依赖性可能解释了在D-P图中观察到的图案。
We report the results of video observations of tiny (diameter less than 100 m) near-Earth objects (NEOs) with Tomo-e Gozen on the Kiso 105 cm Schmidt telescope. The rotational period of a tiny asteroid reflects its dynamical history and physical properties since smaller objects are sensitive to the Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effect. We carried out video observations of 60 tiny NEOs at 2 fps from 2018 to 2021 and successfully derived the rotational periods and axial ratios of 32 NEOs including 13 fast rotators with rotational periods less than 60 s. The fastest rotator found during our survey is 2020 HSwith a rotational period of 2.99 s. We statistically confirmed that there is a certain number of tiny fast rotators in the NEO population, which have been missed with all previous surveys. We have discovered that the distribution of the tiny NEOs in a diameter and rotational period (D–P) diagram is truncated around a period of 10 s. The truncation with a flat-top shape is not explained well by either a realistic tensile strength of NEOs or the suppression of YORP by meteoroid impacts. We propose that the dependence of the tangential YORP effect on the rotational period potentially explains the observed pattern in the D–P diagram.