Copyright:William Vrbasso
中文翻譯:
在遙遠的宇宙中，我們發現了一個紅色的“怪物”，其實它不是一隻可怕的怪物哦！這個名為 Cometary Globule CG 4 的星雲距離我們1300光年，位於小犬座（Puppis）。CG 4 是一個分子雲，在這裡，氫氣變得很冷，會聚在一起形成小顆粒，最終變成恆星。CG 4 看起來像一顆彗星，它的頭部直徑有1.5光年，而尾巴卻長達8光年！為了讓你有個概念，從地球到太陽的距離大約只需8分鐘。天文學家認為，這個彗星狀星雲的尾巴可能是受到附近超新星爆炸的影響，或者是熱烈而巨大的恆星發出的輻射影響的。事實上，CG 4 和其他星雲都朝向位於Gum Nebula中心的Vela超新星殘骸，而位於 CG 4 以外超過一億光年的螺旋星系 ESO 257-19 也完全安全，不用擔心這個“怪物”。
原文:
Is this a cosmic monster ready to devour an unsuspecting galaxy? Thankfully, that is not the case. The red “monster” shown in the featured image is Cometary Globule CG 4, 1,300 light-years away in the Constellation Puppis. CG 4 is a molecular cloud, where hydrogen becomes cold enough to form molecules that can be brought together by gravity to create stars. The shape of CG 4 resembles that of a comet, but its head is 1.5 light-year in diameter and its tail is 8 light-years long; for comparison, the distance from the Earth to the sun is only 8 light-minutes. Astronomers believe that the tail of a cometary globule could have been shaped by a nearby supernova explosion or by irradiation from hot, massive stars. Indeed, CG 4 and other nearby globules point away from the Vela Supernova Remnant, at the center of the Gum Nebula. The edge-on spiral galaxy, ESO 257-19, is more than a hundred million light-years beyond CG 4, and is completely safe from the “monster”.
來源:NASA每日圖片
