金字塔山上的北斗七星
(原标题: Big Dipper over Pyramid Mountain)
2023-12-10
浏览次数: 15
你第一次学会辨认这群恒星是什么时候？虽然世界各地的许多人都很熟悉，但不同的文化将这个星象与不同的图标和民间传说联系在一起。这些星星在美国被称为北斗七星，是1922年国际天文学联合会指定的大熊星座的一部分。这些恒星公认的名字是（从左到右）Alkaid、Mizar/Alcor、Alioth、Megrez、pheecda、Merak和Dubhe。当然，任何星座的恒星都不可能有物理上的联系。但令人惊讶的是，大多数北斗七星在太空中穿行时似乎都朝着同一个方向前进，这是它们与分布在天空中更大区域的其他恒星共同的特性。对它们共同运动的测量表明，它们都属于一个松散的、邻近的星团，被认为平均只有75光年远，直径高达30光年。这个星团更恰当的名称是大熊座移动星团。这张特色图片拍摄于2017年加拿大阿尔伯塔省金字塔山上空的标志性星星。夜空网络研讨会：APOD编辑将回顾2023年最酷的太空图像
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When did you first learn to identify this group of stars? Although they are familiar to many people around the world, different cultures have associated this asterism with different icons and folklore. Known in the USA as the Big Dipper, the stars are part of a constellation designated by the International Astronomical Union in 1922 as the Great Bear (Ursa Major). The recognized star names of these stars are (left to right) Alkaid, Mizar/Alcor, Alioth, Megrez, Phecda, Merak, and Dubhe. Of course, stars in any given constellation are unlikely to be physically related. But surprisingly, most of the Big Dipper stars do seem to be headed in the same direction as they plough through space, a property they share with other stars spread out over an even larger area across the sky. Their measured common motion suggests that they all belong to a loose, nearby star cluster, thought to be on average only about 75 light-years away and up to 30 light-years across. The cluster is more properly known as the Ursa Major Moving Group. The featured image captured the iconic stars in 2017 above Pyramid Mountain in Alberta, Canada. Night Sky Network webinar: APOD editor to review coolest space images of 2023
© Steve Cullen