With the exception of a few rare cases, all the planets known to astronomer scientists revolve around stars. And these rare exceptions are the so-called wandering planets, torn from their planetary system by extraneous gravitational forces or the energy of some cosmic cataclysm. However, according to research conducted by scientists from the Japanese National Astronomical Observatory of Japan (NAOJ), planets can also form near massive holes, creating huge planetary systems containing thousands of huge and strange worlds.
Under ordinary conditions, the formation of planets occurs in the so-called protoplanetary disks – the rings of cosmic gas and dust surrounding young stars. In these disks, seals arise, which, gradually gaining volume and mass, due to increased intrinsic gravity, attract more and more matter from space. And, in the end, planetary systems arise from such clusters, containing planets of various sizes, sometimes surrounded by their own systems of rings and smaller satellites.
But stars are not the only space objects having gas-dust disks. Such disks, only of much larger sizes, also surround supermassive black holes, which are usually located in the central regions of large galaxies. According to available data, in some cases the mass of matter of disks near black holes can exceed the mass of the Sun by 100 thousand times, which is about a billion times more than the mass of matter contained in the “average” protoplanetary disk surrounding a star.
In their research, NAOJ astronomers applied conventional models describing the processes of planet formation near stars to the medium near supermassive black holes. These models also took into account the characteristic features of the environment in the regions of space adjacent to the black hole; nevertheless, the calculation results of these models indicate that, under certain coincidence conditions, planetary systems can actively form near black holes.
The most productive in terms of the formation of their own planets should be black holes located in the center of active galaxies, the so-called active galactic nuclei (Active Galactic Nuclei, AGN). Since the density of dust clouds in such regions is high enough, the temperature in some regions where intense radiation from the central part of the quasar does not reach should be very low. And in such areas in space ice forms, which envelops dust particles, which allows them to stick together with each other and greatly facilitates and accelerates the process of planet formation.
According to the models, planetary systems can form around active black holes over a period of hundreds of millions of years, which is just an instant on the cosmic time scale, and, judging by the amount of matter near black holes, the number of these planetary systems will significantly exceed the largest and largest densely populated stellar planetary system.
“Our calculations show that within 10 light years of a black hole, tens of thousands of planets can form in a fairly short period of time,” says Eiichiro Kokubo, lead researcher, “And there will be no small planets in these systems, the mass itself the smallest of them will be at least 10 times the mass of the Earth. ”
Currently, scientists do not yet have direct evidence of the existence of planetary systems in black holes, and there are currently no opportunities to find such systems given the level of development of modern astronomical technology. However, knowing that this is entirely possible is just the first step to finding the planets that are the property of black holes in the distant or not very distant future.