Black Hole Mass Gap

Black Hole Mass Gap

Recently, Astronomers spotted unusual object falling in the black hole ‘mass gap’.

  • Object resides in a binary system within the star cluster NGC 1851
  • Its companion is a millisecond pulsar – a rapidly spinning neutron star that emits regular pulses of radio waves.
  • By studying the pulsar’s orbital motion, astronomers estimated the mass of the unknown object to be between 2.09 and 2.71 solar masses. This places it within the mass gap.

Mass Gap: Gap between the mass of the Neutron star and the Black hole 

  • Cosmic object with strong gravity that nothing can escape from it, not even light.
  • Boundary of no escape is called the event horizon.
  • Intensity of a black hole – “20 times the sun’s mass could fit easily in a 16 km ball”.
  • Since no light can escape, none can bounce back. This makes the black hole invisible to our eyes and telescopes that we rely on.
  •  They are so dense  and their gravitational pulls so strong, that their cores are permanently shrouded from the universe
  • Mass of small black holes – around 5 to 20 times the mass of the sun (solar mass);
  • Types of black hole:
    • Stellar Black Hole: Formed by the collapse of a single massive star.
    • Intermediate Black Hole: Masses between 100 and 1,00,000 times that of the sun.
    • Supermassive Black Hole: Masses ranging from millions to billions of times that of the sun, found at the centres of most galaxies. 
  • Created after a star dies violently after a supernova explosion.
  • Densest known stellar objects in the universe, second only to the black holes.
  • Extremely strong magnetic fields, much stronger than those of regular stars.
  • These magnetic fields can give rise to intense radiation emissions, including beams of electromagnetic radiation and particle streams, which are observable as pulsars
  • Maximum mass is thought to be around 2.2 solar masses.
Black Hole                     Neutron Star
Larger  mass or sizeSmaller mass or size
Less brighterMore brighter
Created after a star dies violently after a supernova explosionCreated after a star dies violently after a supernova explosion
Not solid objectsDensest solid matter in space
Trap all the surrounding light that crosses its vicinityDo not trap all the surrounding light that crosses its vicinity

Read more about: Black Hole

Source: The Hindu


Previous Year Question

What is the purpose of ‘evolved Laser Interferometer Space Antenna (eLISA) project?

[UPSC Civil Services Exam – 2017 Prelims]

(a) To detect neutrinos
(b) To detect gravitational waves
(c) To detect the effectiveness of missile defence system
(d) To study the effect of solar flares on our communication systems

Answer: (b)


Practice Question

Consider the following statements:
1. The first black hole discovered was Cygnus X-1.
2. Neutron stars have weak  magnetic field than normal stars
Which of the statements given above are correct?

 
 
 
 

Question 1 of 1

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