Supermassive black hole at heart of Milky Way revealed for the first time
- Scientists captured a direct image of Sagittarius A* using the Event Horizon Telescope
- It is some 26,000 light years away and is 4 million times more massive than the sun
For the first time ever, scientists have captured a direct image of the supermassive black hole that dwells at the heart of our Milky Way galaxy.
Some 26,000 light years away, the black hole – named Sagittarius A*, or Sgr A* – has a diameter 17 times that of the sun but is 4 million times as massive. Its extremely strong gravity pulls nearby gas and dust towards it, which swirl around the black hole at nearly the speed of light, get superheated and glow.
The image was released at simultaneous press conferences held by seven research institutions across the globe on Thursday.
This is the second major discovery made by the Event Horizon Telescope (EHT), a global network of telescopes based at different locations, from Hawaiian mountains to the Chilean desert to the South Pole.
During an unprecedented, week-long observation campaign in April 2017, scientists used eight synchronised telescopes – which have a combined diameter as big as the Earth and resolution high enough to see a baseball on the moon – to zoom in on two supermassive black holes: one at the centre of our galaxy, and the other in the nearby galaxy Messier 87 (M87*).
The latter’s picture was released in 2019. In comparison, Sgr A* is more difficult to observe. Despite being much closer to us, it is relatively small and therefore the brightness of the surrounding gas has been changing rapidly, said Jiang Wu from the Shanghai Astronomical Observatory, during an online press briefing organised by the observatory.