An international group of astrophysicists said they were able to detect the hallmarks of black hole event horizons. With their help, they unmistakably separate them from neutron stars. These stars are space objects that are comparable in mass and size to black holes. And today this sign is considered to be the most stable sign of stellar mass black holes. A black hole is considered as an exotic space object.
It does not have a solid surface and thus it refutes general relativity. But without a solid surface, black hole was enclosed in an invisible boundary called the event horizon. Nothing can escape the border.
And only one black hole could be seen by the scientists using ambient radiation in radio waves, its mass is 6 billion times the mass of the Sun. But those black holes that have a mass ten times the mass of the Sun must bend time and space around them at least ten thousand trillion times more than such a supermassive black hole does. Focusing on that fact, the astronomers are confident in the need to study extreme cosmic behavior.
When small black holes collide with each other, gravitational waves are formed. Their presence is a short-lived phenomenon, it only lasts a fraction of a second, but it can provide definitive proof of the existence of a stable stellar mass black hole in X-rays.
A neutron star with a dense surface is also capable of glowing in X-rays. It accretes matter from a nearby star in a similar way that is explained by the high efficiency of converting rest-mass energy into radiation.
For the astronomers to prove the existence of stellar mass black holes, they need to be able to distinguish black holes from neutron stars. A group of astronomers was able to do it. They analyzed X-ray data provided by the Rossi X-Ray Timing Explorer satellite that is no longer in service.
With the help of images, the scientists were able to determine the absence of a solid surface in the observed X-rays and found a strong signature of the accretion of the starry sky, they are massive black holes.