Blanets: Worlds Around Black Holes

Context: 

A 2019 study by a Japanese scientist theorised that planets could also be formed in the massive dust and gas clouds found near supermassive black holes.

About Blanets

• It is a theoretical type of planet that orbits around a black hole instead of a star or brown dwarf.
  • Blanets would be unlike any conventional planet and could emerge an entire new class of objects in astronomical science.

Formation Of Blanets

• They could be formed around relatively low-luminosity active galactic nuclei during their lifetime.
• The Process: It would be similar to planet formation as a black hole is surrounded by massive amounts of dust and gas which bears similarities to protoplanetary disks around young stars.
• Distance: Blanets would need to form around 100 trillion kilometres away from a black hole to survive.
• Scale of the process: A blanet would need to form during the lifetime of active galactic nuclei (around a hundred million years) thus possessing a really short window for formation.
• Relative velocity of the dust particles: The critical velocity of the dust particles in the cloud must be less than about 80 meters per second with the rate of collisions being higher than for a conventional planet.

Characteristics Of Blanets

• Large size: They grow faster and can reach sizes up to 3,000 times the mass of Earth because of the constant wind of fresh dust material supplied by the radiations from the active galactic nuclei
  • Without this dust wind, blanets would grow to no more than six times the mass of Earth
• Orbital Period: Blanets  will have an extremely long orbital period, taking around a million years to complete an orbital revolution.
• Differentiation: The gaseous envelope of a blanet should be negligibly small compared with the blanet mass therefore they cannot be like Jupiter or Neptune. 

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