一颗罕见的恒星逃离了银河系中心的超大质量黑洞

一颗罕见的恒星逃离了银河系中心的超大质量黑洞

This may be the luckiest star in the universe.

这可能是宇宙中最幸运的恒星。

After all, it's not every day that anything escapes the clutches of a supermassive black hole, much less a massive celestial body.

毕竟，并不是每天都有什么东西能逃脱超大质量黑洞的魔爪，更不用说一个巨大的天体了。

In fact, in a research paper published online in Cornell's arXiv, scientists suggest the "hyper-velocity" star dubbed S5-HVS1 may be the first one detected exiting from a black hole.

事实上，在康奈尔大学网站上发表的一篇研究论文中，科学家们提出，这颗被称为S5-HVS1的“超高速”恒星可能是第一个从黑洞中被探测到的恒星。

And what an exit it was. In the paper, partly titled "The Great Escape," researchers suggest it's moving at the ferocious rate of more than 1,000 miles per second.

这是一个多么好的出口啊。在这篇部分名为《大逃亡》的论文中，研究人员表示，它正在以每秒1000多英里的惊人速度移动。

The center of the galaxy isn't the kind of place stars emerge from in one piece. (Photo: sripfoto/Shutterstock)

The star likely needed every ounce of that momentum to make its "great escape" from no less than the supermassive black hole that lurks at the heart of our own galaxy, the Milky Way. That area of space is better known for devouring stars than setting them free.

这颗恒星可能需要每一盎司的动量才能从潜伏在我们银河系中心的超大质量黑洞中“大逃亡”出来。这片区域更出名的是吞噬恒星，而不是释放它们。

And that would be largely due to the supreme reign of a supermassive black hole, dubbed Sagittarius A* (pronounced "Sagittarius A star") — a gravitational golem with a mass around 4 million times that of our sun.

这在很大程度上要归功于一个超大质量黑洞——人马座a *(发音为“人马座a星”)的至高无上的统治地位。人马座a *是一个引力傀儡，其质量大约是太阳的400万倍。

Researchers made the "serendipitous discovery" while working on the Southern Stellar Stream Spectroscopic Survey, a collaboration of more than 30 international scientists that maps stellar streams in the Milky Way.

这项“意外发现”是研究人员在进行“南方恒星流光谱调查”时发现的。“南方恒星流光谱调查”是由30多位国际科学家合作完成的，他们绘制了银河系的恒星流图。

A close-up photo of the black hole at the heart of Sagittarius A*. (Photo: National Science Foundation)

One of those streams suggested a star was hurtling outward from the very heart of the galaxy.

其中一条流表明，一颗恒星正从银河系的中心向外疾驰。

"When integrated backwards in time, the orbit of the star points unambiguously to the Galactic Centre, implying that S5-HVS1 was kicked away from Sgr A* with a velocity of $1,800 km/s and travelled for $4.8 M years to the current location," the study abstract reads.

该研究摘要写道:“如果时光倒流，这颗恒星的轨道明确指向银河系中心，这意味着S5-HVS1以1800公里/秒的速度被Sgr A*踢出，并以480万美元的速度运行到目前的位置。”

And it's not just that the star muscled its way out of the grasp of Sgr A*. The galaxy's core happens to be riddled with smaller but still powerful black holes. In fact, a recent study pegs the black hole population at the heart of our galaxy at somewhere around 10,000.

这不仅仅是因为恒星从Sgr A*的掌控中挣脱出来。星系的核心碰巧布满了更小但仍然强大的黑洞。事实上，最近的一项研究表明，位于银河系中心的黑洞数量约为1万个。

So what does a black-hole dodging star do for an encore — besides, of course, spending the next few millions years congratulating itself?

那么，一颗正在躲避黑洞的恒星要如何再来一次呢?

Even this star appears a little directionless now that its long struggle with dark powers is at an end. According to the researchers, it has spent the last 4.8 million years roaring through space. Maybe that's how long it takes — and how fast one has to go — before being comfortable with a black hole in the rearview mirror.

即使是这颗恒星，在它与黑暗力量的长期斗争结束后，也显得有点迷失了方向。据研究人员称，在过去的480万年里，它一直在太空中咆哮。也许这就是在汽车后视镜上发现黑洞之前需要的时间和速度。