Scientists have published the first photo of a giant (scientifically – supermassive) black hole, lurking in the very center of the Milky Way – our galaxy.

The mass of this cosmic object called Sagittarius A* (that’s right, with an asterisk) is 4 million (!) times greater than the mass of our Sun.

The picture shows the central dark region (central brightness depression), where this black hole lives. She is surrounded by a ring of bright light, which emits superheated gas, which is accelerated under the influence of incredible gravitational forces.

To understand the scale, this ring is comparable in size to the orbit of Mercury revolving around the Sun – about 60 million km across.

Fortunately for earthlings, the monster is very far from us, over 26 thousand light years, so there is no danger of being sucked into this hole.

In 2019, astronomers have already managed to make a portrait of another supermassive black hole – Messier 87, or simply M 87, which is a thousand times the mass of Sagittarius and 6.5 billion times the mass of our Sun, however, it is located further, already in another galaxy .

“The new photo is special because it is ‘our’ supermassive black hole,” says one of the founders of the EHT project, professor of astrophysics Heino Falke. “This hole lives, so to speak, in our backyard, and if you want to understand how in general, black holes live and work, it is she who will be able to tell you about this, because we see her in all details.

By itself, photographing a black hole is already a huge technological achievement. Despite its colossal size, Sagittarius A* appears as a tiny dot in the sky, and it takes an incredible degree of resolution to see it in detail.

To do this, the EHT used a technology called very long baseline radio interferometry (VLBI).

In essence, this technology allows the use of a network of radio antennas spaced over a large distance, which together form a radio telescope the size of our entire planet.

Thus, the angle of observed outer space can be cut down to microarcseconds – thousandths of a second of arc. Such a narrow focus increases visual acuity so much that if it were a person, he could see a donut on the surface of the moon.

But even with such farsightedness, it took complex algorithms and endless hours of computer calculations to create a picture of a black hole from a few petabytes (one petabyte equals a million gigabytes) of collected data.

In fact, since a black hole bends light, only its shadow can be seen, but the brightness of the matter surrounding this shadow and sloshing outward into a ring called an accretion disk gives away the location of the black monster itself.

If you compare the images of Sagittarius and M87, at first glance it may seem that there is not much difference between them, but in fact it is not.

Both black holes were observed at the same time – in early 2017, but compared to Sagittarius, the more massive M87 looked almost static.

But the structure of the ring of hot gas around Sagittarius changed a thousand times faster.

This was especially noticeable in the computer models created by astrophysicists, which allow you to appear, as it were, in the center of our galaxy and observe this black hole with your own eyes (albeit capable of seeing in radio bands).

These rapid changes around Sagittarius A* are precisely the reason why astrophysicists worked much longer to create the image of this black hole than in the case of M87, because data processing required much more effort.

Scientists have long suspected that supermassive black holes prefer to live in the center of galaxies, because it is there that gravitational forces arise that accelerate stars to a speed of 24 thousand km / s (our Sun, for comparison, “crawls” through the galaxy at a speed of only 230 km /with).

However, in awarding astrophysicists Reinhard Genzel and Andreu Ghez in 2020 for their work on Sagittarius A*, the Nobel Committee deliberately avoided the phrase “black hole” and only mentioned a “supermassive compact object” in case there was some other explanation for this exotic phenomenon. . Today, however, all doubts have finally disappeared.

Already this August, the new James Webb Telescope (JWST), the largest space telescope with the largest mirror, will turn its gaze to Sagittarius A*.

While this $10 billion orbiting infrared observatory lacks the resolution to directly image a black hole and its accretion disk, its ultra-sensitive instruments will help astronomers study in detail the behavior and properties of the hundreds of stars around a black hole.

Scientists even hope to find star-sized black holes and clumps of invisible or black matter in this region of the Milky Way.