(Yicai Global) April 11 --  Chinese astronomers have made contributions to a global effort to take  the first-ever image of a supermassive black hole at the heart of a  distant galaxy called M87.

The photo, captured by a  network of eight linked telescopes called the Event Horizon Telescope,  was unveiled yesterday, state-backed Xinhua News Agency reported. 

The experiment required  years of work from more than 200 scientists, including 16 Chinese ones,  who helped with data collection at high-altitude sites such as volcanoes  in Hawaii and mountains in Spain's Sierra Nevada, as well as data  analysis.

The black hole is located about 55 million light-years from Earth, with a mass 6.5 billion times that of the Sun. 

"This is the first direct  visual evidence about black holes obtained by humans, confirming that  Einstein's theory of general relativity still holds in extreme  conditions," said Shen Zhiqiang, head of Shanghai Astronomical  Observatory.

Black holes are cosmic  objects that carry an enormous mass but are extremely small, and they  produce a gravitational force that even light cannot escape from. Albert  Einstein's theory of general relativity predicted the existence of  these regions of spacetime almost a century ago, and scientists say that  they power some of the most extreme phenomena in the universe.

"The dark area and the  ring of the black hole have opened a window for us to reconstruct its  process of gobbling surrounding material and understand the strange  events during this process better in the future," said Lu Rusen, a  researcher with the SAO.

The successful project is just the beginning of collaboration on the EHT, said Shen, adding that more "exciting results" are expected to follow in near future. 

It took about two years to  develop the photo, partly because the amount of data from a five-day  collection effort amounted to an equivalent of streaming almost 2  million hours of high-definition movies. 

"We have achieved  something presumed to be impossible just a generation ago," EHT project  director Sheperd S. Doeleman told Xinhua. "Breakthroughs in technology,  connections between the world's best radio observatories, and innovative  algorithms all came together to open an entirely new window on black  holes and the event horizon." The event horizon is a notional boundary  around a black hole beyond which no light can escape. 

Editor: Emmi Laine