Copyright:Martin Pugh
中文翻譯:
在遙遠的宇宙中，有一個非常微弱的行星狀星雲叫做 Abell 7，距離我們大約有1,800光年。它位於獵犬座的南方，仰望星空時可以找到它，就在獵兔座的方向。這幅深邃的望遠鏡圖像展示了這個大約有8光年直徑的圓形星雲，周圍點綴著散落的銀河系星星。星雲內部的美麗圖案是通過長時間曝光和專門的濾光片拍攝的，這樣我們能捕捉到氫和氧原子的發光。否則，Abell 7實在太微弱了，肉眼根本看不見。行星狀星雲代表著星星演化中的一個迅速階段，未來50億年後，我們的太陽也會經歷這個階段，當時中心的恆星會拋開外層。Abell 7的年齡約為20,000年，但它的中心星球已經有10億年的歷史了，看起來像一顆逐漸褪色的白矮星。
原文:
Very faint planetary nebula Abell 7 is about 1,800 light-years distant. It lies just south of Orion in planet Earth’s skies toward the constellation Lepus, The Hare. Posing with scattered Milky Way stars, its generally simple spherical shape about 8 light-years in diameter is revealed in this deep telescopic image. The beautiful and complex shapes seen within the cosmic cloud are visually enhanced by the use of long exposures and narrowband filters that capture emission from hydrogen and oxygen atoms. Otherwise Abell 7 would be much too faint to be appreciated by eye. A planetary nebula represents a very brief final phase in stellar evolution that our own Sun will experience 5 billion years hence, as the nebula’s central, once sun-like star shrugs off its outer layers. Abell 7 itself is estimated to be 20,000 years old. But its central star, seen here as a fading white dwarf, is some 10 billion years old.
來源:NASA每日圖片
