千呼万唤始出来。
北京时间4月10日21时，全球同时发布了首张黑洞照片。
Via Xinhua
Via Global Times
Taking a photo of a black hole, once considered impossible, has become reality, as astronomers worldwide successfully captured the first-ever event horizon of the M87, a black hole at the center of the Virgo A galaxy of and presented the results in simultaneous press conferences around the world on Wednesday.
给黑洞拍照，这项不可能完成的任务如今已经成为现实。来自世界各地的天文学者通过合作在周三全球多地的新闻发布会上公布了人类历史上首次一个位于室女座A星系M87黑洞的视界照片。
Chinese space experts hailed the event as a milestone, and said it is the most direct evidence of the existence of the black hole.
中国空间专家称赞这样的天文盛事为证明黑洞存在提供了最直接的证据。
The results of the international collaboration under a project codenamed Event Horizon Telescope (EHT) were presented simultaneously at a press conference at the Shanghai Astronomical Observatory with the Chinese Academy of Sciences (CAS), at 9pm Wednesday [13:00 Universal Time], one of the seven designated international research bodies. Others included Greenland Telescope Denmark in Lyngby, Denmark and the US National Science Foundation in Washington, DC.
北京时间周三晚上9点，“事件视界望远镜”的国际合作项目的科研成果发布。中国上海的中科院上海天文台是全球7个负责发布的科研机构中的一个，这7个机构还包括位于丹麦灵比的格林兰望远镜站和美国华盛顿的国家科学基金会。
The black hole, as indicated by its name, is so dark that taking a photo of it is impossible. Because the pull of gravity of the black hole is so immense that nothing escapes, not even electromagnetic radiation such as X-rays, light and radio waves, it makes our direct detection of the object impossible, according to the Dubai-based Science Alert website.
黑洞，正如其名，因为自身过于黑暗而无法实际拍照。黑洞的引力极大，没有任何人类已知的物质能够逃逸，连电磁波都不可以，这样直接侦测黑洞本身一直都是不可能的任务，位于迪拜的科学预警网站 Science Alert 介绍。
Although we cannot see the extremely dark object, by taking a photo of its “shade,” we can better understand the black hole, verify its existence, and even calculate its approximate diameter, Jiao Weixin, a space science professor at Peking University, told the Global Times on Wednesday.
北京大学空间科学教授，焦维新介绍说：我们无法看到黑洞，但是通过拍摄它在周围天体上投射的自旋阴影，我们能够更好理解黑洞本身，证明它的存在，甚至推算出它的大概半径。
The EHT is an international collaboration to pursue a long-standing goal in astrophysics to directly observe the immediate environment of a black hole with angular resolution comparable to the event horizon, according to the EHT website.
“事件视界望远镜”是一项国际合作的大型项目，其目的是构建和视界相匹配的高角分辨能力来直接观测黑洞极近环境。
To achieve that, the EHT has been adopting a technique known as the very-long-baseline interferometry (VLBI), linking radio dishes across the world to create an Earth-sized interferometer in order to measure the size of the emission regions of the two super-massive black holes with the largest apparent event horizons: Sagittarius A* at the center of our galaxy, the Milky Way and M87 at the center of the Virgo A galaxy.
为了实现这一目标，项目串联遍布全球的射电望远镜组成了一个地球直径大小的干涉器，从而实现对于两个距离人类最近的黑洞的观测，分别是银河系的人马座A*和位于室女座A星系的M87。
Only by forming such an Earth-sized interferometer--that is to say, to turn all radio telescopes located across the globe to look in the same direction--to all focus one single object at one time, we can achieve such a high resolution, powerful enough to actually see the curves of light in space, the inner ring of which is the event horizon, and to conclude that the center of such curved light is the black hole itself, Jiao noted.
只有通过形成一个地球半径大小的干涉器系统，让分布在地球各地的射电望远镜在同一时间射向同一目标，我们才能够取得足够强大的干涉能力和分辨率，来看到由于黑洞存在所造成的引力场蜷曲，蜷曲内侧就是我们所谓的“视界”，从而由此来判断其中心阴影处就是黑洞的本身。
The more distant these radio telescopes are, the better angular resolution they can get—meaning, a clearer capture of the distant object, Chen Xuelei, a research fellow with the CAS National Astronomical Observatories in Beijing, told the Global Times on Wednesday.
射电望远镜彼此距离越长，获得的角分辨率越好，得到的遥远目标的成像就越清晰，国家天文台研究员陈学雷介绍说。
Chen noted that, although such an Earth-sized interferometer is the best we can use at present, it is possible in the future to have extraterrestrial satellite-boasting large-scale radio telescopes in space to achieve better angular resolution for the study of black holes.
虽然目前地球半径大小的干涉器是人类最好的解决方案，但是陈学雷预测，在未来，地外基于卫星的大规模射电望远镜用于黑洞研究的可能也是存在的。
The resolution of the telescope should be 50 microarcseconds. To put that into perspective, it's the equivalent of being able to see a grapefruit on the surface of the Moon, it said.
EHT望远镜的分辨率达到50微秒。这样的分辨率能让科学家从地球看清月球上的一粒草莓。
Rather than an optical photo, the visual material achieved through the interferometer would be a model based on data and calculations, Chen said.
我们将看到的是干涉器基于数据和计算推算生成的影像资料而不是我们日常所见的光学照片，陈学雷说道。
Shen Zhiqiang, deputy head of the Shanghai Astronomical Observatory, said there are eight telescopes in six EHT array sites around the world, including the South Pole Telescope in the South Pole, and James Clerk Maxwell Telescope in Hawaii.
据中科院上海天文台副台长、研究员沈志强介绍，“事件视界望远镜”是由国际上可以在230GHz或更高频率的亚毫米波上工作的射电望远镜所组成的VLBI（甚长基线干涉）阵列。目前包括分布在全球六个地方的8个射电望远镜（阵）：南极的SPT、智利的ALMA（阵）和APEX、墨西哥的LMT、美国亚利桑那的SMT、美国夏威夷的JCMT和SMA（阵）和西班牙的30米IRAM。
Shen said although the Shanghai-based Tianma Telescope is not a member of the EHT project, the East Asia VLBI network, consisting of the Tianma Telescope and radio telescopes in South Korea and Japan, carried out a large number of 22 GHz and 43 GHz mapping monitors before and after the EHT observation, which contributed to the EHT results.
沈志强说虽然上海的天马望远镜（65米射电望远镜）不是“事件视界望远镜”的成员之一，但它以另一种形式与此次黑洞观测事件“结缘”。天马望远镜最高工作频率是43GHz，因此不在“事件视界望远镜”之列。但是，天马望远镜与日韩射电望远镜组成的东亚VLBI网在此次“事件视界望远镜”观测前后开展了大量的22GHz和43GHz成图监测，就目前已完成的观测来看，天马望远镜的作用非常明显。
图文：GT, Xinhua