2017年IAO理论高年组第4题-美国日食

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低年组对应问题：2017年IAO理论低年组第4题-美国日食

英文题目

β-4. Eclipse in USA. A little more than two months ago, on August 21, 2017 from West to East of the USA territory a total solar eclipse was observed. The middle line of the track of the eclipse is shown schematically on the map. Below are four pictures taken by the Bulgarian-Russian group of observers who were near the West coast, in the state Oregon, through which the Moon’s shadow ran almost along the latitude φ=45°. The local time (UT-07) Of the shots is indicated below each image. At the moment of totality the Sun was in the South-Eastern part Of the sky, in χ=59,5° from the South in azimuth, at an altitude of h = 41.9°above the horizon. By using the data and making calculations, estimate:

4.1. the speed of the Moon’s shadow in the state Oregon;

4.2. the width of the path of the total eclipse (in km) on its territory.

IAO2017Tβ-4

中文题目

β-4 美国的日食 两个多月前，即2017年8月21日，从美国西部到东部的地区，观测到日全食。日食轨道的中间线在地图上示意性地显示。以下是保加利亚-俄罗斯观察员小组在俄勒冈州西海岸附近拍摄的四张照片，月球的影子几乎沿着纬度φ=45°线行进。拍摄的当地时间（UT-07h）在每张图像下方显示。在整体时刻，太阳位于天空的东南部，在方位角上距离南方χ=59.5°，在地平线以上h=41.9°的高度。 通过使用数据并进行计算，估算：

4.1。 俄勒冈州月球影子的速度;

4.2。 其领土上日全食（以千米为单位）的路径宽度。