PARIS • Astronomers yesterday unveiled the first photo of a black hole, one of the star-devouring monsters scattered throughout the universe and obscured by impenetrable shields of gravity.
The image of a dark core encircled by a flame-orange halo of white-hot gas and plasma looks like any number of artists' renderings over the last 30 years.
But this time, it's the real deal.
Scientists have been puzzling over invisible "dark stars" since the 18th century, but never has one been spied by a telescope, much less photographed.
The super-massive black hole now immortalised by a far-flung network of radio telescopes is 50 million light years away in a galaxy known as M87.
"It's a distance that we could have barely imagined," said Dr Frederic Gueth, an astronomer at France's National Centre for Scientific Research (CNRS) and co-author of studies detailing the findings.
Most speculation had centred on the other candidate targeted by the Event Horizon Telescope - Sagittarius A*, the black hole at the centre of Earth's own galaxy, the Milky Way. By comparison, Sag A* is only 26,000 light years from Earth.
Locking down an image of M87's super-massive black hole at such distance is comparable to photographing a pebble on the Moon.
European Space Agency astrophysicist Paul McNamara called it an "outstanding technical achievement".
It was also a team effort.
"Instead of constructing a giant telescope that would collapse under its own weight, we combined many observatories," said Dr Michael Bremer, an astronomer at the Institute for Millimetric Radio Astronomy in Grenoble.
Over several days in April 2017, eight radio telescopes in Hawaii, Arizona, Spain, Mexico, Chile and the South Pole zeroed in on Sag A* and M87. Knit together "like fragments of a giant mirror", in Dr Bremer's words, they formed a virtual observatory some 12,000km across - roughly the diameter of Earth.
In the end, M87 was more photogenic. Like a fidgety child, Sag A* was too "active" to capture a clear picture, the researchers said.
"The telescope is not looking at the black hole per se, but the material it has captured", a luminous disk of white-hot gas and plasma known as an accretion disk, said Dr McNamara, who was not part of the team. "The light from behind the black hole gets bent like a lens."
The unprecedented image - so often imagined in science and science fiction - has been analysed in six studies co-authored by 200 experts from about 60 institutions and was published yesterday in Astrophysical Journal Letters.