Understanding the cosmos: Bizarre flash of light traced back to kilonova a billion light years away

Understanding the cosmos: Bizarre flash of light traced back to kilonova a billion light years away

Subject : Science and Technology

Context-

• A flash of light in the sky that astounded scientists by lasting close to a minute has been traced back to an explosion a billion light years away. The discovery has broken several assumptions about powerful explosions in the universe.

About the findings-

• The source was found to be an astronomical event called a kilonova. The source was relatively closer- only 1 billion light years away.
• Kilonovae is also known for its red colours, which is a signature of the rare, heavy elements like gold produced in their ejecta. These clues suggested that the source could be a kilonovae
• The event produced very heavy elements about 1,000 times the mass of the Earth. This supports the idea that kilonovae are the main factories of gold in the universe.
• These explosions take place during the merger of two neutron stars or a neutron star and a black hole.
• Researchers could not identify whether the GRBs came from the merger of two neutron stars or a neutron star colliding with a black hole.
• A neutron star is the collapsed core of a massive supergiant star, whereas a black hole is a place in space where gravity pulls so much that even light can not get out.
• Stellar black holes are made when the centre of a very big star falls in upon itself or collapses.
• When this happens, it causes a supernova — an exploding star that blasts part of the star into space.
• Both kilonova and supernova produce the most energetic form of light called Gamma-ray burst (GRBs), the former is known to generate shorter pulses lasting less than 2 seconds. This new event, however, generated a GRB that lasted roughly 50 seconds.
• GRBs can be divided into two classes: Long-duration (2 seconds to several minutes) and short-duration (a few milliseconds to 2 seconds) bursts.
• This breaks the long-held traditional GRB paradigm that massive star collapses produce long GRBs and supernovae and neutron star mergers produce short GRBs and kilonovae.