charles 2009-3-27 10:44
女巫帚星雲
NGC 6960: The Witch's Broom Nebula
[img]http://i19.tinypic.com/30w03rq.jpg[/img]
影像提供與版權: T. A. Rector (U. Alaska), WIYN, NOAO, AURA, NSF
[color=navy]Explanation: [/color]
[color=dimgray]Ten thousand years ago, before the dawn of recorded human history, a new light must suddenly have appeared in the night sky and faded after a few weeks. Today we know this light was an exploding star and record the colorful expanding cloud as the Veil Nebula. Pictured above is the west end of the Veil Nebula known technically as NGC 6960 but less formally as the Witch's Broom Nebula. The rampaging gas gains its colors by impacting and exciting existing nearby gas. The supernova remnant lies about 1400 light-years away towards the constellation of Cygnus. This Witch's Broom actually spans over three times the angular size of the full Moon. The bright star 52 Cygnus is visible with the unaided eye from a dark location but unrelated to the ancient supernova. [/color]
[color=navy]說明:[/color]
[color=dimgray]一萬多年前，人類開始用文字來記錄歷史之前的某一天，夜空中突然出現一道亮光，然後在幾個星期之後慢慢變暗消失。現在，我們知道這道光這是恆星爆炸的結果，而且還殘留下五顏六色的擴散雲氣，稱為面紗星雲。上圖中是面紗星雲的西緣，正式名稱為 NGC 6960，但它更常被稱呼為女巫帚星雲。當這些向外擴張的氣體衝擊並激發周圍的氣體之後，就會出現許多顏色。這個超新星爆炸遺骸位於天鵝座，距離我們大約1400光年遠。這支女巫掃帚的視角大約是滿月的三倍。照片中那顆亮星是天鵝座52號星，在沒有光害的地方用肉眼就可以看得到它，不過它和這個古老的超新星爆炸沒有關係。 。[/color]
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size][color=white][size=1]
[/size][/color]