中文翻譯:
在遙遠的星空中，NGC 474這個神奇的星系正經歷著一些奇妙的事情。這個星系有著多層次漂亮的光芒，看起來非常復雜，這跟一些拍得不太深的圖片中，令人驚訝的平滑外表形成了鮮明的對比。有研究者認為，這些光環可能是小星系在過去十億年中被吸收後留下的潮汐尾巴。或者，也有可能就像水池中的波紋一樣，NGC 474正在和其旁邊的一個螺旋星系發生碰撞，這種碰撞在它的星系中產生了密度波。無論真正的原因是什麼，這幅圖片驚人地展示了某些橢圓星系的光環是多麼的複雜，我們自己的銀河系（Milky Way）也是一個例子，它的光環同樣充滿了驚喜。NGC 474的直徑大約有250,000光年，距離我們大約1億光年，朝向魚座（Pisces）那裡。
原文:
What’s happening to galaxy NGC 474? The multiple layers of emission appear strangely complex given the relatively featureless appearance of the elliptical galaxy in less deep images. The cause of the shells is a topic of research, but they are possibly tidal tails related to debris left over from absorbing numerous small galaxies in the past billion years. Alternatively, the shells may be like ripples in a pond, where the ongoing collision with the spiral galaxy just to the right of NGC 474 is causing density waves to ripple through the galactic giant. Regardless of the actual cause, the featured image dramatically highlights the increasing evidence that the halos of some elliptical galaxies are surprisingly complicated. Similarly, the halo of our own Milky Way Galaxy is one example of such unexpected intricacies. NGC 474 spans about 250,000 light years and lies about 100 million light years distant toward the constellation of the Fish (Pisces).
來源:NASA每日圖片
