June 21 () –
Sagittarius A star, the supermassive black hole located at the center of our galaxy, the Milky Way, It came out of a long period of dormancy about 200 years ago.
A team led by Frédéric Marin, a CNRS researcher at the Strasbourg Astronomical Observatory (CNRS/University of Strasbourg, in France), reports in the journal Nature the past awakening of this gigantic object, which is four million times more massive than the Sun.
Over a one-year period in the early 19th century, the black hole gobbled up cosmic objects that came too close to it., before re-entering a state of stillness. No effect was felt on Earth, since the distance between it and our planet is too great (about two billion times the distance from Earth to the Sun).
However, the detected X-ray echo, emitted some 200 years ago, reveals that the original intensity was at least a million times greater than that currently emitted by this black hole. To get an idea of the increase in intensity of the X-ray emission when the black hole came out of its resting state, it is as if a single firefly hidden in a forest suddenly became as bright as the Sun, reports the CNRS it’s a statement.
These findings explain why the galactic molecular clouds close to the Sagittarius A star shine brighter than usual: it is because they are reflecting the X-rays emitted by the black hole 200 years ago.
To carry out their research, the scientists used NASA’s IXPE (Imaging X-ray Polarimetry Explorer) satellite, which for the first time was able to detect the polarization of this X-ray light with great precision and also determine its source, something that until then had been impossible.
Like a compass, polarized X-ray light points directly at its source, Sagittarius A star, despite the fact that it is practically extinct. Scientists continue their work on Sagittarius A star to try to determine the physical mechanisms necessary for a black hole to go from a resting state to an active one.