Copyright:
Stefan Thrun
中文翻譯:
在遙遠的宇宙深處，有一個名叫NGC 2685的特別星系，它有著一種奇特的形狀，像螺旋一樣，圍繞著它的中心旋轉著明亮的星星、氣體和塵埃。這種海洋般的繞行結構甚至有一個好玩的名字：極環星系！科學家們認為，這也許是因為它從另一個星系捕獲了一些星際材料，然後這些材料就變成了可愛的環狀結構。不過，NGC 2685並不是新的，它的結構非常穩定，而且存在了很長很久，它的寬度將近50,000光年，距離我們地球約4000萬光年。哇，這麼大的星系，你想像得到嗎？這個星系也被稱為赫利克斯星系（Helix galaxy）或阿普336（Arp 336），它坐落在北天的北斗七星（Ursa Major）星座裡，是一個非常神奇的宇宙寶藏！
原文:
What is going on with this galaxy? NGC 2685 is a confirmed polar ring galaxy – a rare type of galaxy with stars, gas and dust orbiting in rings perpendicular to the plane of a flat galactic disk. The bizarre configuration could be caused by the chance capture of material from another galaxy by a disk galaxy, with the captured debris strung out in a rotating ring. Still, observed properties of NGC 2685 suggest that the rotating helix structure is remarkably old and stable. In this sharp view of the peculiar system also known as Arp 336 or the Helix galaxy, the strange, perpendicular rings are easy to trace as they pass in front of the galactic disk, along with other disturbed outer structures. NGC 2685 is about 50,000 light-years across and 40 million light-years away in the constellation of the Great Bear (Ursa Major). Piece it All Together: Astronomy Puzzle of the Day
來源:NASA每日圖片
