来自瑞典的明亮英仙流星群

探索宇宙（universe）！每天都会展示一张不同且迷人的宇宙图像或照片，并附上一段由专业天文学家（astronomer）撰写的简短说明。

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

说明：一年一度的英仙流星群（Perseids）以其明亮且快速的流星（meteor）而闻名，它们从英仙座（Perseus）这一英雄星座（constellation）中的辐射点来到地球（Earth）的天空。这一广受欢迎的北半球夏季天象，是由周期彗星（periodic comet）109P/Swift-Tuttle沿轨道抛洒的尘埃颗粒在地球稠密大气层中汽化，在夜空中划出短暂而美丽的轨迹所形成的。这张合成图像拍摄于8月12日流星雨活动极大期附近，记录了两颗明亮的英仙流星以及其中一颗流星在瑞典格里斯勒港（Grisslehamn）沿海村庄附近水面上的倒影。这些流星几乎与场景中最亮的恒星（star）河鼓二（Altair）一样明亮，并与银河（Milky Way）暗淡而弥散的背景一同出现。今年，该流星雨的极大活动期恰逢朔（new moon），因此英仙流星的闪光未受明亮月光的干扰。对于许多观星者来说，这个英仙流星闪耀的夜晚，紧随他们观测一场备受期待的日食（solar eclipse）中新月的剪影之后。

Explanation: Known for its bright and fast meteors, the annual Perseid Meteor Shower comes to planet Earth's skies from a radiant in the heroic constellation Perseus. The popular northern summer celestial spectacle is created as grains of dust cast off along the orbit of periodic comet 109P/Swift-Tuttle vaporize in Earth's dense atmosphere, tracing brief, but beautiful streaks through the night. Taken near the shower's peak of activity on August 12, this composite image recorded two bright perseid meteors and one meteor's watery reflection from a location near the coastal village of Grisslehamn, Sweden. Almost as bright as Altair, brightest star on the scene, the meteors appear along with the faint, diffuse background of the Milky Way. This year, the shower's peak activity coincided with a New Moon, so perseid meteor flashes were undiminished by bright moonlight. And for many skywatchers, this night of bright perseid meteors followed their viewing of the silhouette of the New Moon in a much anticipated solar eclipse.