This is the first image of the black hole at the heart of the Milky Way

 For years, the supermassive black hole in the dark center of the Milky
Way galaxy has been theorized about and studied — and finally, it's been
captured in an image.

"We finally have the first look at our Milky Way black hole, Sagittarius A*,"
an international team of astrophysicists and researchers from the Event
Horizon Telescope team announced on Thursday.

"It's the dawn of a new era of black hole physics," it added.

The black hole is often referred to as Sgr A*, pronounced sadge ay star. Its
mass is about 4 million times that of the sun, and it's about 27,000 light
years from Earth, according to MIT.

Black holes have long been a source of public fascination, but they also pose
notorious challenges to researchers, mainly because their gravitational fields
are so strong that they either bend light or prevent it from escaping
entirely. But scientists have been able to detect and study them based on the
powerful effects they exert on their surroundings.

In the case of Sgr A*, scientists have previously observed stars orbiting
around the Milky Way's center. Now they have a direct view of what Feryal
Özel, a professor of astronomy and physics at the University of Arizona,
called the "gentle giant" itself.

Putting the size of the black hole into an Earthling's perspective, the team
said that seeing it from the surface of our planet would be like trying to
spot a donut on the moon.

"What made it extra challenging was the dynamic environment of Sgr A*, a
source that burbled then gurgled as we looked at it," Özel said, "and the
challenges of looking not only through our own atmosphere, but also through
the gas clouds in the disk of our galaxy towards the center. It took several
years to refine our image and confirm what we had, but we prevailed."

More than 300 researchers collaborated on the effort to capture the image,
compiling information from radio observatories around the world. To obtain the
image, scientists used observations from April 2017, when all eight
observatories were pointed at the black hole.

"Although we cannot see the black hole itself, because it is completely dark,
glowing gas around it reveals a telltale signature: a dark central region
(called a 'shadow') surrounded by a bright ring-like structure," the EHT team
said in its announcement.

The researchers announced the news Thursday morning at the National Press Club
in Washington, D.C., but it was simultaneously released around the world, in a
series of news conferences held in Mexico City, Shanghai, Tokyo, and other
cities.

"We were stunned by how well the size of the ring agreed with predictions from
Einstein's Theory of General Relativity," said EHT Project Scientist Geoffrey
Bower, from the Institute of Astronomy and Astrophysics at the Academia Sinica
in Taipei.

The discovery comes three years after the Event Horizon Telescope
Collaboration released the first-ever image of a black hole — but that work
focused on the center of galaxy Messier 87, tens of millions of light-years
away from Earth in the Virgo cluster of galaxies.

Commenting on the similarities of the two images, of a dark shadow surrounded
by a bright ring, Özel stated, "It seems that black holes like donuts."

Still, she said, the two black holes are very different from one another — for
one thing, the Milky Way's black hole isn't as voracious.

"The one in M87 is accumulating matter at a significantly faster rate than Sgr
A*," she said. "Perhaps more importantly, the one in M87 launches a powerful
jet that extends as far as the edge of that galaxy. Our black hole does not."

Copyright 2022 NPR. To see more, visit https://www.npr.org.