Copyright:Miguel Claro
原文:
In only about 12,000 years Vega will be the North Star, the closest bright star to our fair planet’s North Celestial Pole. By then, when you fix your camera to a tripod long exposures of the night sky will show the concentric arcs of star trails centered on a point near Vega as Earth rotates on its axis. Of course, presently the bright star conveniently near the North Celestial Pole is Polaris, but that will change as the Earth’s axis of rotation precesses, like the wobble of a spinning top with a precession period of about 26,000 years. If your camera is ready now and you don’t want to wait 12,000 years for Vega to be the North Star, consider this ingenious demonstration of contemporary star trails (left) versus star trails reminiscent of the year 14000 CE. Both were recorded this April at the Alqueva Dark Sky Reserve in Alentejo, Portugal. To produce the more Vega-centric star trails of the distant future, astronomer Miguel Claro combined the rotation of two startracking camera mounts to create the apparent shift in the North Celestial Pole. (Addendum: Thanks to APOD readers who note that when Vega is the North Star it will also appear near the same position that Polaris is now relative to the landscape.)
中文翻譯:
🔭✨ 大約還要12,000年，Vega 會成為北極星，即我們美麗星球的北天極附近最近的明亮恆星。那時候，如果你將相機固定在三腳架上，執行長時間曝光拍攝夜空，將會顯示出以Vega為中心的星軌圓環，因為地球的自轉。不過，當前，方便地位於北天極附近的明亮星星是 Polaris，但隨著地球自轉軸的進行，這一切都會改變，這就像一個旋轉的陀螺，擁有約26,000年的進行週期。
如果你的相機已經準備好，而你又不想等到12,000年讓Vega成為北極星，可以考慮這個巧妙的示範：當前的星軌（左）與預示著14,000年CE的星軌。這兩者都是在葡萄牙 Alqueva Dark Sky Reserve 於四月拍攝的。為了展示更偏向Vega的未來星軌，天文學家 Miguel Claro 結合了兩個追星相機支架的旋轉，創造出北天極的明顯移動效果。（附註：感謝APOD的讀者指出，當Vega成為北極星時，與當前Polaris的相對位置在景觀上也會相近。）
#Vega #北極星 #星軌 #Astronomy #天文學 #AlquevaDarkSkyReserve #StarTrails #Polaris #宇宙探索 #NaturePhotography #葡萄牙 #星空攝影 #FutureAstronomy
來源:NASA每日圖片
