Astronomers reveal first image of black hole at Milky Way's centre

An international team of astronomers on Thursday unveiled the first image of a supermassive black hole at the centre of our own Milky Way galaxy -- a cosmic body known as Sagittarius A*.

The image -- produced by a global team of scientists known as the Event Horizon Telescope (EHT) Collaboration -- is the first, direct visual confirmation of the presence of this invisible object, and comes three years after the very first image of a black hole from a distant galaxy.

"For decades, we have known about a compact object that is at the heart of our galaxy that is four million times more massive than our Sun," Harvard University astronomer Sara Issaoun told a press conference in Garching, Germany, held simultaneously with other media events around the world.

"Today, right at this moment, we have direct evidence that this object is a black hole."

Black holes are regions of space where the pull of gravity is so intense that nothing can escape, including light.

The image thus depicts not the black hole itself, because it is completely dark, but the glowing gas that encircles the phenomenon in a bright ring of bending light.

As seen from Earth, it appears the same size as a donut on the surface of the Moon, Issaoun explained.

"These unprecedented observations have greatly improved our understanding of what happens at the very centre of our galaxy," EHT project scientist Geoffrey Bower, of Taiwan's Academia Sinica, said in a statement.

The research results are published in The Astrophysical Journal Letters.