Observation and Interpretation of Leonid Impact Flashes on the Moon in 2001
Observation and Interpretation of Leonid Impact Flashes on the Moon in 2001
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DOI：
10.1086/341625
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发表时间：
2002-09
期刊：
影响因子：
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通讯作者：
J. L. Ortiz;J. A. Quesada;J. Aceituno;F. Aceituno;L. B. Rubio
中科院分区：
文献类型：
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作者：
J. L. Ortiz;J. A. Quesada;J. Aceituno;F. Aceituno;L. B. Rubio
我们目前的观测记录在2001年11月从西班牙狮子座的月球撞击闪光。11月18日，观测到四次撞击闪光。同一天晚上还记录到另一个闪光，似乎与撞击有关，当晚还有两个闪光可能是撞击性质的，但并非毫无疑问。11月19日，观测到另一次闪光，很可能是撞击造成的。最亮的撞击闪光达到了5.2 ± 0.3等的峰值亮度（V）;它在峰值亮度前0.02秒有一个非常暗淡的前兆，并且有一个非常持久的余辉，在亮度振荡的情况下保持可见超过600 ms;这种独特且意想不到的行为挑战了当前的撞击闪光模型。其他闪光没有显示出这种行为，并保持可见几十毫秒。采用1999年狮子座流星雨的发光效率（2 × 10-3），我们的观测可以用来估计流星体通量。这些观测结果与11月18日18：15 UT时质量大于2 × 10-8 kg km-2 hr-1的0.1流星体通量一致，前提是使用1.69的质量指数。流量和质量指数都与2001年从地球上几个地点进行的流星观测相吻合。
We present observations of lunar Leonid impact flashes recorded in 2001 November from Spain. Four impact flashes were detected on November 18. Another flash was also recorded on the same night, which appears to be impact related, and two more on that night are possibly, but not unambiguously, of impact nature. On November 19 another flash was detected, which very likely resulted from an impact. The brightest impact flash reached a peak brightness of 5.2 ± 0.3 mag in V; it had a very dim precursor just 0.02 s prior to peak brightness and had a very long lasting afterglow that remained visible for more than 600 ms with oscillations in brightness; this unique and unexpected behavior challenges current models of impact flashes. The other flashes did not show such a behavior and remained visible for a few tens of milliseconds. Adopting the luminous efficiency derived for the 1999 lunar Leonids (2 × 10-3), our observations can be used to estimate meteoroid fluxes. The observations are compatible with a flux of 0.1 meteoroids of mass larger than 2 × 10-8 kg km-2 hr-1 on November 18 at 18:15 UT, provided that a mass index of 1.69 is used. Both the flux and the mass index agree with meteor observations carried out in 2001 from several locations on Earth.