‘The Unicorn’, closest known black hole to Earth

Context:

Scientists named a newly discovered and the closest to our solar system black hole, in the Milky Way galaxy, as Unicorn. It may be the smallest known black hole.

What is Unicorn?

• Characteristics: It is roughly three times the mass of our sun.
• The black hole is located about 1,500 light-years away from Earth.
• A luminous star is known as a red giant, orbits with the black hole in a binary star system, named V723 Mon.
• It is nicknamed as the Unicorn’ partly because V723 Mon is in the Monoceros constellation that translates to the unicorn and partly because it is a unique system.
• The Unicorn is said to be the smallest known black hole.
• It is thought to be formed by the gravitational collapse of a single star.
• ‘The Unicorn’ falls into a “mass gap”, that is between, the largest-known neutron at around 2.2 times the mass of our sun and the smallest black holes at around five times the sun’s mass.
• Its strong gravity causes tidal distortion which alters the shape of its companion star.
• It makes the star elongated rather than spherical and causes its light to change as it moves along its orbital path.

Blackhole and its subtypes

• A black hole is a region of space-time where gravity is extremely strong that no object can escape from it.
• Types: There are two types of black holes which become three with the discovery:
  • Stellar-mass black holes: These are the black holes with a mass of fewer than 100 times that of the Sun.
  • Supermassive black holes (SMBH): These are the ones with a mass greater than 100,000 times that of the Sun.
  • Intermediate-mass black holes (IMBHs): These are a class of black holes with a mass approximately 100 to 100,000 times that of the Sun.
• Both stellar black holes and SMBHs are commonly found.