nebulae

Extragalactic nebula is invisible to the naked eye.

我们用看不到河外星系的。

You can see nebulae in the clear summer sky.

在晴朗的夏夜可以看到天上的星云。

A bit of mould is a pleiad of flowers;a nebula is an ant-hill of stars.

一粒霉菌一簇美不胜收的花朵，一撮星云无数天体的蚁聚。

The tiny but intriguing yellowish arc visible near the blue nebulae marks young variable star R Coronae Australis.

在蓝色星云附近，微但迷人的微黄色弧状可见物标出年轻可见恒星南冕座R星的位置。

As our nebula began to collapse under its own gravity and spin faster, a dense clump of matter formed in the center. It's called a protostar.

当我们的星云在自身重力作用下崩溃和更加快速地旋转时，星云中心密集的物质块。这叫做原恒星。