螺旋星系

新年伊始，NASA的哈勃太空望远镜拍到了一团旋转的星尘和气体，被称为螺旋星系ESO021-G004，捕捉到的图像令人震惊，提醒着我们地球其实是多么渺小和脆弱。

On the brink of a new year , NASA 's Hubble Space Telescope snapped a swirling mass of star dust and gas , known as spiral galaxy ESO 021-G004 , and the resulting image is so gob-smacking , it 's an instant reminder of how tiny and fragile our home really is .

请注意，形状正常前瞻性的螺旋星系发生了变化。

Note that the shape of the normal-looking spiral galaxy has changed .

类似的效应也会出现在恒星周围的残馀盘，以及螺旋星系周围的气体圆盘上。

A similar effect flattens the debris disks around stars and the gaseous disks of spiral galaxies .

一个美丽的螺旋星系，恒星群从明亮核心中扫过。

A beautiful spiral galaxy with its stars contained in large arms sweeping out from a bright core .

解说：这片灰蒙蒙的岛宇宙是在地球的夜空中最明亮的螺旋星系之一。

Explanation : This dusty island universe is one of the brightest spiral galaxies in planet Earth 's sky .

银河是螺旋星系；那是如果观看从它在远处会类似螺旋。

The Milky way is a spiral galaxy ; that is , if viewed from afar it would resemble a spiral .

另一种则是：椭圆星系是较晚才出现的，它们是螺旋星系合并的后果。

The other is that ellipticals are relative latecomers , having been produced as a result of the merging of spiral galaxies .

因为多数的黑暗物质晕最终都带有角动量，我们要问：为什麽还会有星系不是螺旋星系？

Because most dark matter halos end up with some angular momentum , one has to wonder why all galaxies aren 't spirals .

编辑是一个“宏伟设计”的螺旋星系，这意味着它幽雅武器袅袅一路下跌到其中心。

M81 is a " grand design " spiral galaxy , which means its elegant arms curl all the way down into its center .

碰撞也会改变星系的外形，特别是当两螺旋星系融合后可能会产生单一的椭圆星系。

Collisions also can transform the shape of galaxies involved ; specifically , the merger of two spiral galaxies may produce a single elliptical galaxy .

大多数的人认为我们自身的银河系是个单纯的螺旋星系，但天文学家现在知道它其实是个棒旋星系。

Most people think of our own galaxy , the Milky Way , as a pure spiral , but astronomers now know it is actually a barred spiral .

选择矮行星也有不足：这就是矮行星里的恒星不按照规则的圆形轨道运动，像螺旋星系里的恒星都沿着同一方向运动那样。

The disadvantage : the stars in dwarf galaxies don 't move in tidy circular orbits , traveling in the same direction the way stars in spiral galaxies do .

它之所以属于螺旋星系范畴，是因为相对于那些更趋近于球体（或椭球）的星系来说，它的主要部分更平。

It remains in the spiral category because of the flatness of the main disk of stars as opposed to the more spherically rotund ( or ellipsoidal ) class of galaxies called " ellipticals " .

有螺旋形构造的星系；包括年纪较小的恒星在中心从年纪较大的中螺旋出去的臂状物。

A galaxy having a spiral structure ; arms containing younger stars spiral out from old stars at the center .

而就如同银河星系一样，原本螺旋状的水母星系从它的气体和尘埃中创造新的恒星。

A jellyfish galaxy was once a spiral like the Milky Way , spawning new stars from its gas and dust .