According to observations of stellar velocities, it is assumed that in the centers of nearby galaxies M31 and M32 there are black holes with masses of 10 to 100 million Suns. In the center of our Galaxy there is also a compact object weighing about 4 * 10 ^ 6 solar masses. According to scientists, this is most likely a black hole, although the presence of a concentrated star cluster is possible.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.