The stars are known as Cepheid variables.

这些恒就是我们熟知的造父变。

There are more than a thousand known cataclysmic variables.

已知的激变变一千种。

The system belongs to a kind of binary star known as cataclysmic variable.

该系统属于一种被称为激变变的双。

Only 12 or so have orbital periods below 75 minutes.

只有12种左右的激变变拥有低于75分钟的轨道周期。

Skowron explained that Cepheids are giant stars that are far brighter than the sun.

斯考伦解释说，造父变是比太阳明亮得多的巨。

And... And right in the middle, there's a variable star that I discovered.

而… … 而在正中央有一颗我所发现的变。

They observed variable stars in the Andromeda Galaxy that allowed them to get the distance to the galaxy.

他们观测了仙女座系中的变，这使得他们能够到达系的距离。

And it was, in fact, a variable star.

事实上，它是一颗变。

" Var" here stands for " variable." Hubble had found a variable star in the Andromeda Nebula.

“Var”在这里代表“变”。哈勃望远镜在仙女座云中发现了一颗变。

And since there were pulsating Cepheid stars whose actual distances we already knew, this let us build a cosmic measuring stick.

既然我们已经知道这些有规律脉动的造父变的实际距离，这就给我们造出一把宇宙测量尺。

Cepheids are quite rare, but at least one of them is well known to us—Polaris, the pole-star, is a Cepheid.

造父变非常罕见, 但至少其中一颗是我们所熟知的 - - 极北极就是造父变。

Now if two Cepheid stars are pulsating at the same rate, and one's dimmer than the other, that means one is actually farther away.

如果两个造父变以相同的速率脉动，并且其中一个比另一个更加暗淡，这就意着更暗的那个更远。

I observe from seven or eight till about two in the morning, with a view to my great work on variable stars.

我从七八点观察到凌晨两点左右， 以期完成我在变方面的伟大工作。

If two Cepheid stars are pulsating at the same rate, and one's dimmer than the other, that means one is actually farther away.

如果两颗造父变以相同的速率脉动，并且一颗比另一颗暗， 这意着一颗实际上距离更远。

It was the review of a pamphlet by an American astronomer, in which the author announced a conclusive discovery with regard to variable stars.

那是一位美国天文学家对一本小册子的评论，作者在书中宣布了关于变的一个结论性发现。

She noticed that a type of star known as a Cepheid variable (after the constellation Cepheus, where it first was identified) pulsated with a regular rhythm-a kind of stellar heartbeat.

她注意到，有一种名叫造父变（以仙王座命名，第一颗造父变就是在那里发现的）的恒在有节奏地搏动——一种体的“心跳”。

Actual variable stars do exist, but Tabby's Star doesn't fit that profile, it's what's known as an F-type main-sequence star, and shouldn't behave anything like this.

实际的变确实存在， 但 Tabby's Star 不符合这种情况，它是所谓的 F 型主序， 不应该有这样的行为。

In the early 1900s, astronomer Henrietta Swan Leavitt realized a class of stars called Cepheids pulsate, bright and dim, and every Cepheid that pulsates at the same rate has the same brightness.

1900 年代早期，天文学家 Henrietta Swan Leavitt 发现一系列名为造父变，它们有规律地变亮和变暗，并且每个造父变以相同的速率脉动就会有着相同的亮度。

'I have made an amazing discovery in connexion with the variable stars, ' he exclaimed. 'It will excite the whole astronomical world, and the world outside but little less.

“我在变方面有了惊人的发现，”他惊呼道。 “它会激发整个天文界的兴奋，而外面的世界却不会那么兴奋。”

'I am preparing a work on variable stars. There is one of these which I have exceptionally observed for several months, and on this my great theory is mainly based.

“我正在准备一部关于变的作品。其中之一是我几个月来特别观察到的，我的伟大理论主要基于此。