The first image of the black hole at the center of our galaxy, the Milky Way, was revealed on Thursday by an international group of researchers. The technical prowess turns out to be in complete agreement with the predictions of astrophysicists and amazes the scientific community.
The black hole sits at the center of Sagittarius A*, a radiofrequency burst 27,000 light years from Earth. Our galaxy orbits around this object which until now has defied the most powerful telescopes due to its low luminosity.
The Event Horizon Telescope (EHT), a network of 11 radio telescopes distributed from one end of the Earth to the other, managed to pierce this fuzzy halo to detect a shadowy circle: the “shadow” of the black hole. This silhouette is defined by the cloud of gas that spins around the supermassive object.
“Wow! said Sara Issaoun, a member of the EHT team, speaking at a press conference. This is the first image of the supermassive black hole at the heart of our galaxy, the Milky Way, Sagittarius A*. For decades, we have known that there was a compact object, 4 million times more massive than our Sun. Today, at this very moment, we have direct evidence that this object is a black hole. »
Sagittarius A* is 1000 times less massive than the black hole at the center of the galaxy Messier 87, whose image, also taken by the EHT, made headlines in 2019. It was then the first image of a black hole never obtained.
The discovery announced on Thursday turns out to be, at the technical level, a much more difficult undertaking. If Sagittarius A* were the size of a doughnut, Messier 87*, by comparison, would be the size of a soccer stadium.
Despite these differences in scale, the two silhouettes are extremely similar. This observation is significant for astrophysics. “When you get to the edge of a black hole, gravity takes over,” said Issaoun.
Julie Hlavacek-Larrondo, a black hole specialist at the University of Montreal, calls Thursday’s results a “huge achievement.” She attended the digital press conference from a meeting of the Center for Research in Astrophysics of Quebec.
“We listened to the presentation together, and when the image was revealed, the whole room applauded,” she says enthusiastically.
Further details will follow.