A kilometre-sized Kuiper belt object discovered by stellar occultation using amateur telescopes
A kilometre-sized Kuiper belt object discovered by stellar occultation using amateur telescopes
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DOI：
10.1038/s41550-018-0685-8
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发表时间：
2019-01
期刊：
影响因子：
14.1
通讯作者：
K. Arimatsu;K. Tsumura;F. Usui;Y. Shinnaka;K. Ichikawa;T. Ootsubo;T. Kotani;T. Wada;K. Nagase-K.
中科院分区：
文献类型：
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作者：
K. Arimatsu;K. Tsumura;F. Usui;Y. Shinnaka;K. Ichikawa;T. Ootsubo;T. Kotani;T. Wada;K. Nagase-K.
柯伊伯带天体(KBO)被认为是早期太阳系的遗迹，它们的大小分布为探索外太阳系的形成和演化提供了机会。特别是，千米大小(半径=1-10公里)的KBO的大小分布代表了行星形成时初始行星微小大小的特征。这些千米大小的KBO极其微弱，不可能直接探测到它们。相反，监测恒星掩星事件是发现这些小型KBO的一种可能方式。然而，到目前为止，还没有观测到半径为1-10公里的KBO掩星事件的证据。在这里，我们报道了第一次用半径为1.3公里的KBO探测到单个候选掩星事件，它是由两个低成本的小型望远镜和商用CMOS相机联合提供的。从这次探测，我们得出半径超过Km的KBO的表面数密度是。这种表面数密度有利于在半径1-2公里处具有过量特征的理论尺寸分布模型。如果这是一次真实的探测，这意味着小行星在它们失控的生长阶段之前，在原始的外太阳系中成长为千米大小的物体，并仍然是今天柯伊伯带的主要种群。
Kuiper belt objects (KBOs) are thought to be the remnant of the early solar system, and their size distribution provides an opportunity to explore the formation and evolution of the outer solar system. In particular, the size distribution of kilometre-sized (radius = 1-10 km) KBO represents a signature of initial planetesimal sizes when planets form. These kilometre-sized KBOs are extremely faint, and it is impossible to detect them directly. Instead, monitoring of stellar occultation events is one possible way to discover these small KBOs. Hitherto, however, there has been no observational evidence for the occultation events by KBOs with radii of 1-10 km. Here we report the first detection of a single occultation event candidate by a KBO with a radius of1.3 km, which is simultaneously provided by two low-cost small telescopes coupled with commercial CMOS cameras. From this detection, we conclude that a surface number density of KBOs with radii exceedingkm is. This surface number density favours a theoretical size distribution model with an excess signature at a radius of 1-2 km. If this is a true detection, this implies that planetesimals before their runaway growth phase grow into kilometre-sized objects in the primordial outer solar system and remain as a major population of the present-day Kuiper belt.