Indian astronomers part of Nasa team detect radiation from death of a star over 5 billion years ago – India Today

Part of an astronomy team, Indian astronomers have detected a very short, powerful burst of high-energy radiation that lasted for about a second. The event had been travelling for nearly half the present age of the universe before it hit Earth. The universe is nearly 14 billion years old.

The burst was first detected by Nasas Fermi Gamma-ray Space Telescope last year. Analysis of the data showed that the shortest Gamma-Ray Burst (GRB) was caused by the death of a massive star. These bursts are considered one of the most powerful events in the universe and can travel across billions of light-years.

Named GRB 200826A, after the date it occurred, researchers released the details of the event in two papers published in Nature Astronomy. While the first paper led by Bin-bin Zhang at Nanjing University in China explores the gamma-ray data. The second, led by Toms Ahumada, a doctoral student at the University of Maryland, describes the GRBs fading multiwavelength afterglow and the emerging light of the supernova explosion that followed.

Dr Shashi Bhushan Pandey from Aryabhatta Research Institute of Observational Sciences (ARIES) was part of the study, apart from scientists from other Indian institutions. They showed for the first time that a dying star can produce short bursts too. Such a discovery has helped to resolve the long-standing issues related to gamma-ray bursts. Also, this study triggers to re-analyse all such known events to constrain number densities better, Dr Pandey said.

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 the study, the Ministry of Science & Technology said in a statement.

While the burst was detected for barely a second, astronomers estimate that it 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.

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. 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.

According to the Ministry of Science & Technology, "GRB 200826A was a sharp blast of high-energy emission lasting just 0.65 seconds. After travelling for aeons through the expanding universe, the signal had stretched out to about one-second-long when it was detected by Fermis Gamma-ray Burst Monitor."

The new discovery could help astronomers in understanding the nature of these bursts that are linked to supernovas. The detection of such GRB remains rare compared to exploding stars.

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Indian astronomers part of Nasa team detect radiation from death of a star over 5 billion years ago - India Today