sagitarius A group of astronomers, for 16 years studying the movement of stars around the central area of galaxies, provided evidence that located in the region radio-source Sagittarius_A is indeed a super big black hole.
Interstellar dust is not allowed to monitor the optical processes in the center of the Milky Way, so scientists had to record the infrared radiation range. The objects of study were 28 stars who visit the orbits around Sagittarius_A.

It turned out that the mass of the researched object exceeds the sun at about 4.3 million times and the distance from Earth to the center of the Galaxy is about 27 thousand light-years. However, the primary value of their work is the acknowledgment of the existence of black holes.

The full 35-page, version of the report scientists available for download.