Spiral galaxies are a common galaxy type.

螺旋星系是一种常见的星系类型。

But spiral galaxies are those that look like giant pinwheel.

但是螺旋星系就像巨大的风车一样。

In the 1960s and 1970s, astronomer Vera Rubin was observing spiral galaxies.

在20世纪60年代和70年代，天文学家维拉·鲁宾一直在观察螺旋星系。

Spiral galaxies we've seen: We live in one!

我们见过螺旋星系的——我们就生活在这样一个星系中！

This makes them similar to the stars in the central bulges of spiral galaxies.

这使得它们类似于螺旋星系中央凸起的恒星。

If these two spiral galaxies collided, they would merge into one new elliptical galaxy.

如果这两个螺旋星系相撞，它们会结合成新的椭圆星系。

The arms of spiral galaxies seem to move faster than the laws of physics would allow.

旋状星系的旋臂运行的速度似乎比用物理法则算出的速度快。

It also contains many bright galaxies, including the Leo Triplet, a group of three spiral galaxies.

它也包括很多发光的星系，包括狮子座Triplet，由三个螺旋星系组成的一组。

This is Andromeda, a spiral galaxy roughly the same size and mass as the Milky Way.

这是仙女座，一个大小和质量都跟银河系相差无几的螺旋星系。

About half of spiral galaxies have a straight structure, called a bar, coming out from the center.

大约一半的螺旋星系有一个直的结构，称为棒，从中心出来。