Scientists say they have discovered the closest black hole to Earth.
科学家说，他们发现了离地球最近的黑洞。
 
Black holes are areas in space where gravity is so strong that nothing – not even light – can escape them. They are believed to be formed from collapsed stars.
黑洞是空间中引力如此之强以至于什么都没有——不即使是光——也能逃脱它们。它们被认为是由坍缩的恒星形成的。
 
An international group of astronomers recently announced the discovery of the black hole, which sits about 1,600 light years from Earth. A light year is the distance light travels in one year. In space, light moves about 9.4 trillion kilometers each year.
一个国际天文学家小组最近宣布发现了这个距离地球约 1,600 光年的黑洞。一光年是光在一年内传播的距离。在太空中，光每年移动约 9.4 万亿公里。
 
The researchers named the black hole Gaia BH1. They say it sits in the constellation of Ophiuchus. A constellation is a grouping of stars. The black hole is believed to weigh about 10 times the mass of our sun. The team said it is three times closer to Earth than the previous record-holder.
研究人员将黑洞命名为 Gaia BH1。他们说它位于蛇夫座。星座是一组恒星。据信，黑洞的质量约为太阳质量的 10 倍。该团队表示，它距离地球的距离是之前的记录保持者的三倍。
 
The newly discovered gravitational mass was identified by observing the motion of its orbiting star. The star orbits the black hole at about the same distance as Earth orbits the sun.
新发现的引力质量是通过观察其绕行恒星的运动而确定的。这颗恒星绕黑洞运行的距离与地球绕太阳运行的距离大致相同。
 
Kareem El-Badry is an astrophysicist with the Harvard-Smithsonian Center for Astrophysics and Germany's Max Planck Institute for Astronomy. He was the lead writer of a study describing the discovery in Monthly Notices of the Royal Astronomical Society.
Kareem El-Badry 是哈佛-史密森尼天体物理中心和德国马克斯普朗克天文学研究所的天体物理学家。他是英国皇家天文学会月报中描述这一发现的研究的主要作者。

The black hole was first identified using the European Space Agency's (ESA) Gaia spacecraft. Gaia has already discovered more than 800,000 multi-star systems. El-Badry and his team then sought to confirm the discovery through numerous additional observations over a period of four months. This effort involved six different highly sensitive telescopes across the world.
首先使用欧洲航天局 (ESA) 的盖亚宇宙飞船发现了黑洞。盖亚已经发现了超过 800,000 个多星系统。然后，El-Badry 和他的团队试图在四个月内通过大量额外的观察来确认这一发现。这项工作涉及全球六台不同的高灵敏度望远镜。
 
 
One was the 6.5-meter Magellan Baade telescope, based at the Las Campanas Observatory in Chile. The team also used an instrument on the Gemini North telescope, which is based in Hawaii.
其中之一是位于智利拉斯坎帕纳斯天文台的 6.5 米麦哲伦巴德望远镜。该团队还使用了位于夏威夷的 Gemini North 望远镜上的仪器。
 
The researchers needed such telescopes to effectively observe the orbital motion of the black hole's star. The telescope in Chile and the Gemini instrument were able to provide the astronomers with high-resolution images. The telescopes also collected sensitive data on ultraviolet and near-infrared wavelengths.
研究人员需要这样的望远镜来有效地观察黑洞恒星的轨道运动。智利的望远镜和双子座仪器能够为天文学家提供高分辨率图像。这些望远镜还收集了有关紫外和近红外波长的敏感数据。
 
El-Badry said in a statement the Gemini observations "confirmed beyond a reasonable doubt" that the team had discovered a normal star and at least one black hole. El-Badry added that the black hole appears to be dormant, meaning not currently active.
El-Badry 在一份声明中说，双子座的观测“毫无疑问地证实了”该团队发现了一颗正常的恒星和至少一个黑洞。 El-Badry 补充说，黑洞似乎处于休眠状态，这意味着当前不活跃。
 
When active, black holes give off high-energy light. While dormant, they give off nothing and are difficult to identify.
活跃时，黑洞会发出高能光。虽然处于休眠状态，但它们不会释放任何物质并且难以识别。
 
How did black hole form in our galaxy?
我们的银河系中的黑洞是如何形成的？
 
The scientists said it remains unclear how the black hole formed in our Milky Way galaxy. Examinations of data collected on Gaia BH1 suggests "its existence is difficult to explain" using traditional evolutionary modeling methods, said Tineke Roegiers. She is a project information specialist with the Gaia spacecraft team.
科学家们表示，目前尚不清楚黑洞是如何在我们的银河系中形成的。 Tineke Roegiers 说，对在 Gaia BH1 上收集的数据进行的检查表明，使用传统的进化建模方法“很难解释它的存在”。她是盖亚航天器团队的项目信息专家。
 
The researchers said if the black hole formed the traditional way – from the gravitational collapse of a star – that star would have been at least 20 times the mass of our sun. This means the star would have only lived a short time, maybe only a few million years.
研究人员表示，如果黑洞以传统方式形成——来自恒星的引力坍缩——那颗恒星的质量至少是黑洞的 20 倍我们太阳的质量。这意味着这颗恒星只会存在很短的时间，也许只有几百万年。
 
If both stars had formed at the same time, the scientists say, the massive star would have quickly turned into a "supergiant" and swallowed the other star before it had a chance to fully develop.
如果两颗恒星同时形成，科学家们说，这颗大质量恒星会很快变成一颗“超巨星”还没来得及发育完全就吞噬了另一颗恒星。
 
 
These differences, Roegiers said, "may indicate something important is missing from our current knowledge of black hole formation."
Roegiers 说，这些差异“可能表明我们目前对黑洞形成的了解中缺少一些重要的东西。”
 
El-Badry said the mystery about Earth's closest black hole presents many questions about how it formed, "as well as how many of these dormant black holes there are out there."
El-Badry 说，关于地球最近的黑洞的谜团提出了许多关于它是如何形成的问题， “以及那里有多少这些休眠的黑洞。”
 
He added, "I have been searching for a system like Gaia BH1 for the last four years, trying all kinds of methods – but none of them worked. It has been elating to see this search finally bear fruit."
他补充说，“过去四年我一直在寻找像盖亚BH1这样的系统，尝试了各种方法——但他们都没有奏效。看到这次搜索终于结出了果实，真是令人欣喜若狂。”