A black hole in the Milky Way apparently changed the color of nearby stars

NASA Black Hole Gallery

According to the theory, the black hole launched a powerful jet of gas that tore off the outer layers of the red giants of the galaxy, removing the red part of the star as it made the star hotter and bluer. That is the belief of the astrophysicist at the Polish Academy of Sciences in Warsaw, Michal Zajaček, who published this theory on November 12 in the Astrophysical Journal.

There are no powerful gas jets coming out of Sagittarius today, but above and below the center of the Milky Way are two large bubbles of gamma rays ejecting gas, possibly evidence of the powerful jet that created nearby red giants. to lose their outer layer 4 million years ago.

“The jet prefers to operate on large red giants,” said Zajaček. “They can be effectively removed by the jet.”

Zajaček says red giant stars are more vulnerable than others to these types of jets due to their large size. These types of stars form when the center of smaller stars is so full of helium that it can no longer burn its hydrogen fuel, but instead burns the hydrogen in a layer surrounding the center. This causes the outer layer of the star to expand, cooling its surface and turning it red. The resulting size makes red giants a prime target for jets like Sagittarius A *.

Since these red giants orbit Sagittarius A *, they have to pass through the ray described by Zajaček hundreds or thousands of times before the outer layer is ripped away and the red turns blue. His team calculates that the jet is most effective at removing the outermost layer of red giants within 13 light-years of the black hole.

However, astronomer from the University of California, Los Angeles, Tuan Do, says he believes that “a combination of several mechanisms of this kind may be needed to fully explain the absence of the red giants,” said Science News. He says it is probably different from a jet that caused the lack of red giants further away from the black hole.

Both Do and Zajaček theorize that it may be the work of a large gas disk that orbited the black hole millions of years ago. As the red giants circled the black hole, they probably noticed they were going through the disk, and the disk’s gas may have torn off their outer layers in the process.

For more black hole science, read about the recent discovery of the black hole closest to Earth, then read about this black hole that is nine times larger than the sun bringing in time and space. Check out this black hole that seems to break the laws of nature afterwards.

Wesley LeBlanc is a freelance news writer and guide maker for IGN. You can follow him Twitter @LeBlancWes.