Copyright:Kent Biggs
中文翻譯:
在星空中，有一個美麗的星雲叫做M57，通常被稱為環嵌星雲。它像一個閃閃發光的環，周圍有一些淡淡的外圍光暈。M57其實不是一顆行星，而是我們銀河系裡一顆快要熄滅的恆星的氣體雲。附近還有一個叫做IC 1296的旋渦星系，雖然它看起來和M57差不多大，但實際上它距離我們相當遙遠，大約有兩億光年！如果你仔細觀察圖像，會發現還有其他更加遙遠的星系分布在畫面中，這真是一次美妙的宇宙探險！
原文:
This colorful telescopic view towards the musical northern constellation Lyra reveals the faint outer halos and brighter central ring-shaped region of M57, popularly known as the Ring Nebula. To modern astronomers M57 is a well-known planetary nebula. With a central ring about one light-year across, M57 is definitely not a planet though, but the gaseous shroud of one of the Milky Way’s dying sun-like stars. Roughly the same apparent size as M57, the fainter and more often overlooked barred spiral galaxy at the left is IC 1296. In fact, over 100 years ago IC 1296 would have been known as a spiral nebula. By chance the pair are in the same field of view, and while they appear to have similar sizes they are actually very far apart. At a distance of a mere 2,000 light-years M57 is well within our own Milky Way galaxy. Extragalactic IC 1296 (aka PGC62532) is more like 200,000,000 light-years distant. That’s about 100,000 times farther away than M57 but since they appear roughly similar in size, former spiral nebula IC 1296 must also be about 100,000 times larger than planetary nebula M57. Look closely at the sharp 21st century astroimage to spot even more distant background galaxies scattered through the frame.
來源:NASA每日圖片
