Sean Raymond, an Astrophysicist at the Observatory of Bordeaux, suggests that nearly a million planets supporting life could orbit a black hole.

Black Holes are one of the most amazing concepts and scientists are quite keen to explore more and more about them. We do know that the gravitational pull in these regions of space is so strong that nothing, including electromagnetic radiations, could pass through them but quite a lot of information is missing. A lot of money and time is invested in this search every year but researchers have managed to get a little out of that until now.

Similarly, astronomers dearly want to find some sort of life somewhere else other than the Earth. Despite the fact that they have a huge collection of potential candidates, they haven’t succeeded until now. Raymond combined these two ideas to propose that as much as 1 million habitable planets could be found revolving around a black hole. He talked about that in the following words:

“I think we can learn from the extremes … they are basically the boundaries of the box in which we are searching. This system is one extreme — the most packed imaginable. It’s a fun blend of imagination and science.”

Raymond described four possible situations in which a black hole might act as the central point and multiple planets orbit it. The first one of them involves the replacement of the Sun of our solar system with a ‘Stellar-mass Black Hole’, which has the same mass as the Sun.

This kind of black hole is formed when a giant star collapses in on itself after its death. According to Raymond, there will no massive changes in the orbits of the planets if this happens. However, he mentioned that the life on Earth will be affected because the intensity of light and heat will decrease.

On the other hand, if our sun has an equal-mass black hole orbiting at around 0.1 Astronomical Units from it, some variations will be observed in the orbits of the planets. Considering that the distance of the planets from the sun stays the same, all these worlds will complete a cycle of the central star at a much faster rate.

For instance, our planet (Earth) will complete its orbit in 258 days instead of 365 days. The orbiting time for sun and the black hole will be 2.9 days. This means that either one of them will orbit the other in around 70 hours. Raymond described this by saying,

“That is like bouncing between New York and Miami and back every 2.9 days.”

The third scenario he proposed is based on ‘Supermassive Black Holes’. Their mass ranges from millions to billions of suns. According to astronomers, they exist in the center of most galaxies, if not all. His observations led Raymond to a conclusion that only 6 planets having a mass equal to Earth could fit into the habitable zone of our sun.

He explained in his report that if we replace our sun with a Supermassive Black Hole, 550 Earth-mass planets could fit in stable concentric orbits within the habitable zone of the black hole. He mentioned that one of the ways to create a habitable zone of such a black hole is to place stars between it and the planets. According to his calculations, a ring of 9 sun-like stars can achieve the target of 550 planets if the stars are placed at a distance of 0.5 AU from the black hole. He described the effects that will be observed on such a planet as he said,

“It would be pretty interesting to live on a planet in this system. It would take just a few days to complete an orbit around the black hole — about 1.6 days at the inner edge of the habitable zone and 4.6 days at the outer edge.”

Lastly, he proposed that planets can share a single orbit around a Supermassive black hole. In a ring, which is 1 AU away from the black hole, 42 Earth-mass planets could be present. In order to form a stable ring of planets, all of them must have a uniform mass and they must be evenly spaced in their circular orbit.

He performed his calculations with a million-sun black hole which was surrounded by a ring of 9 sun-like stars. He told the world that as much as 1,000,000 Earth-mass planets could orbit within the habitable zone of the black hole. They will be divided into 400 rings and all of them will have 2,500 planets. All the planets in a single ring will have the same distance as there is between Earth and the Moon.