Lhe detection of this bubble, whose lifetime did not exceed a few hours, could provide information on the behavior of black holes. These astronomical objects are all the more mysterious in that they are literally invisible, their gravitational force being such that not even light can escape.
Sagittarius A*, the supermassive black hole lurking at the heart of the Milky Way, is about 27,000 light-years from Earth. It was detected thanks to the movement of stars orbiting around it. The EHT collaboration, a worldwide network of radio-telescopes, published last May the first image of the ring of material that surrounds the black hole before being absorbed into it.
ALMA, one of these radio-telescopes which is located in Chile, has picked up a “very surprising” signal in the observation data of Sagittarius A *, explained to AFP the astrophysicist Maciek Wielgus, of the German Institute Max Planck for Radio Astronomy.
Speed that “defies the imagination”
A few minutes before ALMA collected this data, the Chandra space telescope detected “a huge emission” of X-rays from Sagittarius A*, he explained.
This burst of energy, believed to be similar to solar storms from the Sun, sent a bubble of gas flying around the black hole at full speed, according to the study published in the journal Astronomy and Astrophysics.
The phenomenon observed for about an hour and a half made it possible to calculate that the gas bubble made a complete orbit of the black hole in just 70 minutes, and therefore at a speed equivalent to 30% of that of light, which goes to 300,000 km per second. A speed that “defies the imagination”, according to Mr. Wielgus.