天空中的日出阴影
(原标题: Sunrise Shadows in the Sky)
2024-09-21
浏览次数: 17
今年9月春分的决定性天文时刻是9月22日12点44分，当太阳在每年一次的地球天空之旅中穿过天球赤道向南移动时。这标志着北半球的秋天和南半球的春天的开始，那时全球的白天和黑夜几乎相等。当然，如果你通过观看日出来庆祝天文季节的变化，你也可以寻找黄昏光线。在任何日出（或日落）的黄昏天空中，黄昏光线的轮廓被云投下的阴影勾勒出来，具有戏剧性的外观。由于透视，平行的云阴影似乎指向太阳升起的地方，在春分日你的地平线上正东方的地方。但在这张六月初拍摄的壮观的日出天空中，平行的阴影和黄昏的光线似乎汇聚在东方地平线上更北的日出。这张构图精美的照片拍摄的是西班牙加泰罗尼亚巴塞罗那省维克镇一座教堂钟楼后面冉冉升起的太阳。
查看原文解释
The defining astronomical moment of this September's equinox is at 12:44 UTC on September 22, when the Sun crosses the celestial equator moving south in its yearly journey through planet Earth's sky. That marks the beginning of fall for our fair planet in the northern hemisphere and spring in the southern hemisphere, when day and night are nearly equal around the globe. Of course, if you celebrate the astronomical change of seasons by watching a sunrise you can also look for crepuscular rays. Outlined by shadows cast by clouds, crepuscular rays can have a dramatic appearance in the twilight sky during any sunrise (or sunset). Due to perspective, the parallel cloud shadows will seem to point back to the rising Sun and a place due east on your horizon on the equinox date. But in this spectacular sunrise skyscape captured in early June, the parallel shadows and crepuscular rays appear to converge toward an eastern horizon's more northerly sunrise. The well-composed photo places the rising Sun just behind the bell tower of a church in the town of Vic, province of Barcelona, Catalonia, Spain.
© Emili Vilamala