Part of: GS Prelims and GS-III – Space
In news A group of astronomers have detected a very short, powerful burst of high-energy radiation that lasted for about a second and had been racing toward Earth for nearly half the present age of the universe.
- The burst detected by NASA’s Fermi Gamma-ray Space Telescope on August 26, 2020, turned out to be one the shortest gamma-ray burst (GRB) caused by the death of a massive star.
- From India, The Inter-University Centre for Astronomy and Astrophysics, Pune (IUCAA), National Centre for Radio Astrophysics – Tata Institute of Fundamental Research, Pune (NCRA) and IIT Mumbai also participated in this work.
- The burst emitted 14 million times the energy released by the entire Milky Way galaxy over the same amount of time, making it one of the most energetic short-duration GRBs ever seen.
What are gamma-ray bursts (GRB)?
- GRBs are the most powerful events in the universe, detectable across billions of light-years.
- Astronomers classify them as long or short based on whether the event lasts for more or less than two seconds.
- They observe long bursts in association with the demise of massive stars, while short bursts have been linked to a different scenario.
- This recent identification of GRBs showed for the first time that a dying star can produce short bursts too.
- When a star much more massive than the Sun runs out of fuel, its core suddenly collapses and forms a black hole.
- As matter swirls toward the black hole, some of it 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.