Sagittarius A * is a huge object located in the center of our galaxy, and has a mass about four million times larger than the Sun. Until now, it was believed that it was a black hole due to the movement of stars around that object.
That assumption was shaken in 2014 as a gaseous cloud known as the G2 approached that supermassive black hole.
Scientists expected that the cloud would be destroyed by the huge gravitational forces of Sagittarius A *, but that did not happen, and G2 survived the close encounter without any problems.
Some scientists now believe that Sagittarius A * is not a black hole at all, but a set of dark matter. Dark matter is invisible and is believed to make up 80 percent of the total matter in the entire universe, but it is very difficult to detect because it does not react to light.
To test their new theory, scientists from the International Center for Relativistic Astrophysics (ICRA) made a simulation in which they put dark matter in the center of our galaxy instead of a black hole, more precisely a strange elementary particle known as “darkino”, which would be denser in the center masses, but less frequently at the ends.
Darkinos are, according to scientists, a type of fermion (particles that cannot have the same quantum state at any given time) and as such are limited in how densely they can be compressed. Therefore, the mentioned G2 gas cloud could survive the passage of the outer parts of the mentioned mass in the center of the galaxy, just as it would enable the survival of nearby stars. It could also explain the rotational curvature of the outer rim of the Milky Way.
While the theory of a supermassive black hole remains the most likely hypothesis, the real answer could be more complex than we think.
This year, scientists suggested that supermassive black holes could form from dark matter, which would explain why they could form so quickly, even before galaxies existed around them.