Betelgeuse, which is red and cool, is an M2.

参宿四，呈红色且很凉，是 M2。

Now, once Betelgeuse has gone, the constellation of Orion will look very different.

一旦参宿四消失不见，猎户座将会看起来很别扭。

Now, when it goes, Betelgeuse will be incredibly bright.

因此当参宿四爆发时，将会无比耀眼。

Betelgeuse will certainly explode some day, but it's too far away to hurt us.

参宿四总有一天会爆炸，但它太远了，伤不到我们。

The nearest likely candidate he added, is Betelgeuse, whose various sputterings have for years suggested that something interestingly unstable is going on there.

他接着说，离我们最近的、很可能有资格的，是猎户座；多年来，它一直在喷出各种东西，表明那里不大稳定，引起了大家的注意。

That could mean any time in the next million years but equally it could explode tomorrow, and Betelgeuse is only 600 light years away.

“随时”的意思是接下来一百万年里的任何一刻，说不定就是明天，而参宿四离我们仅有 600 光年的距离。

For example, Betelgeuse in Orion is a red supergiant, and one of the brightest stars in the sky despite being over 600 light years away.

例如，猎户座中的参宿四是一颗红色的超巨星，尽管它距离我们超过了600光年，但仍然是天空中最亮的恒星之一。

In addition, the star Betelgeuse will have exploded into a supernova by this point and the explosion will be easily visible from Earth even during the daytime.

此外，猎户座 α 星此时将爆炸成一颗超新星，即使在白天，从地球上也很容易看到爆炸。

This is the constellation of Orion and this is Betelgeuse, and we know it's extremely unstable because it's dimmed by about 15% in the last ten years.

那就是猎户星座中的参宿四红巨星，我们目前清楚它极不稳定，这是因为在过去的 10 年里它的亮度降低了大约 15%。

It takes a star 10 to 20 times bigger than our sun to make a supernova, and the nearest possible star of that size is Betelgeuse, which is far too far away.

一颗比我们的太阳大 10 到 20 倍的恒星才能形成超新星，而离我们最近的这种大小的恒星是参宿四，它离我们太远了。