The Discovery of a Faint Glow of Scattered Sunlight from the Dust Trail of the Leonid Parent Comet 55P/Tempel-Tuttle
The Discovery of a Faint Glow of Scattered Sunlight from the Dust Trail of the Leonid Parent Comet 55P/Tempel-Tuttle
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狮子座母彗星 55P/坦普尔-塔特尔的尘埃轨迹中发现了散射阳光的微弱光芒
DOI：
10.1086/309380
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
T. Mukai
中科院分区：
文献类型：
--
作者：
R. Nakamura;Y. Fujii;M. Ishiguro;K. Morishige;S. Yokogawa;P. Jenniskens;T. Mukai
流星云是地球上的观测者所看到的彗星轨道上沿着尘埃轨迹中的小流星体散射的微弱阳光。虽然这些云以前只知道从过去的流星风暴的轶事，我们现在报告的检测流星云的现代技术在彗星55 P/坦普尔-塔特尔，狮子座流星流的父母尘埃轨迹的方向。我们在夏威夷的莫纳克亚山进行的光度观测显示，1998年狮子座流星雨期间，这片云是天空亮度的局部增强。从云的空间范围推导出的轨迹半径约为0.01 Au，与流星雨历史记录绘制的空间范围一致。云的亮度约为背景黄道光的2%-3%，不能用基于1998年天顶每小时速率和流星群指数的简单模型计算来解释。如果云粒子的典型尺寸为10 μm，粒子数密度为0.1，则亮度转化为1.2 × 10-10 m-3的数密度。流星体云将是整个尘埃轨迹的产物，而不仅仅是1998年穿过的那部分。
A meteoric cloud is the faint glow of sunlight scattered by small meteoroids in the dust trail along the orbit of a comet as seen by an earthbound observer. While these clouds were previously only known from anecdotes of past meteor storms, we now report the detection of a meteoric cloud by modern techniques in the direction of the dust trail of comet 55P/Tempel-Tuttle, the parent of the Leonid meteor stream. Our photometric observations, performed on Mauna Kea, Hawaii, reveal the cloud as a local enhancement in sky brightness during the Leonid shower in 1998. The radius of the trail, deduced from the spatial extent of the cloud, is approximately 0.01 AU and is consistent with the spatial extent mapped out by historic accounts of meteor storms. The brightness of the cloud is approximately ~2%-3% of the background zodiacal light and cannot be explained by simple model calculations based on the zenith hourly rate and population index of the meteor stream in 1998. If the typical size of cloud particles is 10 μm and the albedo is 0.1, the brightness translates into a number density of 1.2 × 10-10 m-3. The meteoroid cloud would be the product of the whole dust trail and not only the part that was crossed in 1998.