Supermassive black holes have been theorized and studied for years – and finally, an image of one has been captured.
On Thursday, the Event Horizon Telescope team announced that we have our first look at Sagittarius A*, our Milky Way black hole.
“Blackhole physics is entering a new era,” it added.
Sgr A*, or sadge ay star, is often used to refer to the black hole. According to MIT, it’s about 27,000 light-years from Earth, and it’s about 4 million times the mass of the sun.
In addition to their public fascination, black holes also pose notorious challenges to researchers, because their gravitational fields are so strong that they either bend light or block it from escaping. Nevertheless, scientists have been able to detect and study them because of the effects they have on the surrounding environment.
Researchers previously observed stars orbiting the Milky Way‘s center in the case of Sgr A*. The “gentle giant” itself has been directly observed for the first time, according to Feryal *zel, a professor of astronomy and physics at the University of Arizona.
To put it in Earthling terms, viewing the black hole would be like trying to distinguish a donut on the moon from the surface of our planet.
It took several years to refine our image and confirm what we had, but we succeeded. “The dynamic nature of Sgr A*, which burbled then gurgled as we observed it,” said *zel, “and the challenges of looking not only through our atmosphere, but also through the gas clouds in the disk of our galaxy towards the center, made it much more challenging.”
The researchers collected information from radio observatories all over the world, as well as their own, to capture the image. Scientists used observations of all eight observatories located around the black hole in April 2017 in order to obtain this image.
The EHT team said in its announcement that, although a black hole cannot be seen, glowing gas around it reveals a telltale sign: a dark central region (called a “shadow”) surrounded by a bright ring-like structure.
It was announced at the National Press Club in Washington, D.C., but it was also announced in news conferences around the world, including those in Mexico City, Shanghai, and Tokyo.
EHT Project Scientist Geoffrey Bower, from the Academia Sinica in Taipei, expressed surprise at how well the ring fit Einstein’s Theory of General Relativity.
Scientists released the first-ever image of a black hole three years ago, but it was taken of the center of galaxy Messier 87, tens of millions of light-years away from Earth in Virgo cluster.
“It seems like black holes are like donuts,” says *zel, referring to the similarity of the two images.
But they are very different, she said – for one thing, the milky way’s black hole is not as voracious as the one in the center of our galaxy.
Compared to Sgr A*, M87 accumulates matter much faster. Moreover, the black hole in M87 shoots out a powerful jet that reaches the edge of the galaxy, whereas the one in our galaxy does not.”