Important Facts For Prelims
Binary Merger of Gamma Ray Burst with Kilonova
- 08 Dec 2022
- 4 min read
Why in News?
Recently, a rare astronomical event involving a compact binary merger emitting long Gamma Ray Burst (GRB) twinned with a kilonova emissions was reported. This never before scientifically accepted or proven combination was also confirmed by India’s largest optical telescope, Devasthal Optical Telescope (DOT).
- The GRB lasted for over 50 seconds and identified as GRB211211A.
- Kilonovae occur when two compact objects, like binary neutron stars or a neutron star and a black hole, collide.
What are Gamma-Ray Bursts?
- About:
- GRBs are massive but extremely bright, high-energy short gamma radiations which get released when massive stars collapse or die in the Universe.
- They are the most powerful events in the universe, detectable across billions of light-years.
- A light-year is the distance a beam of light travels in a single Earth year, or 9.5 trillion kilometers.
- Astronomers classify them as long or short based on whether the event lasts for more or less than two seconds.
- Long GRBs:
- They observe long bursts in association with the demise of massive stars.
- When a star much more massive than the Sun runs out of fuel, its core suddenly collapses and forms a black hole.
- Black hole refers to a point in space where matter is so compressed as to create a gravity field from which even light cannot escape.
- As matter swirls toward the black hole, some of that escapes in the form of two powerful jets that rush outward at almost the speed of light in opposite directions.
- Astronomers only detect a GRB when one of these jets happens to point almost directly toward Earth.
- Each jet drills through the star, producing a pulse of gamma rays – the highest-energy form of light – that can last up to minutes. Following the burst, the disrupted star then rapidly expands as a supernova.
- A supernova is the name given to an exploding star that has reached the end of its life.
- Short GRB:
- Short GRB, on the other hand, forms when pairs of compact objects – such as neutron stars, which also form during stellar collapse – spiral inward over billions of years and collide.
- A neutron star comprises one of the possible evolutionary end-points of high mass stars.
- Short GRB, on the other hand, forms when pairs of compact objects – such as neutron stars, which also form during stellar collapse – spiral inward over billions of years and collide.
UPSC Civil Services Examination, Previous Year Question (PYQ)
Q. Recently, scientists observed the merger of giant ‘blackholes’ billions of light-years away from the Earth. What is the significance of this observation? (2019)
(a) ‘Higgs boson particles’ were detected.
(b) ‘Gravitational waves’ were detected.
(c) Possibility of inter-galactic space travel through ‘wormhole’ was confirmed.
(d) It enabled the scientists to understand ‘singularity’.
Ans: (b)