Current Affairs
Daily Bits

‘The Unicorn', closest known black hole to Earth

  • Posted By
  • Categories
    Science & Technology
  • Published
    23rd Apr, 2021


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.

About 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 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 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 the 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.

Blackholeand its subtypes

  • A black hole is a region of space-timewhere 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 witha 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 a black hole with a mass approximately 100 to 100,000 times that of the Sun.
  • Both stellar black holes and SMBHs are commonly found.

Some of the discovered black holes

  • The closest black hole to Earth is a part of the system HR 6819 and is active just 1,000 light-years from earth
  • The smallest known black hole is GRO J0422+32. It was discovered in 1992 at around 7,800 light-years from us.
  • A supermassive black hole called Sgr A* and is 26,000 light-years from Earth. It holds a mass of at least 40 lakh times the Sun’s.
  • The first-ever black hole detected was Cygnus X-1 in 1964.