Astronomers uncover briefest supernova-powered gamma-ray burst

This illustration shows a collapsing Star that is producing two short Gamma-ray Jets. If the jets point toward Earth, we can often see a gammaray burst, which is a brief explosion of Gamma-ray radiation, just before a huge, collapsing star explodes into a supernova. The most well-known supernova-produced Gamma-ray Bursts last more than 2 seconds. However, GRB 200826 lasted just 0.6 seconds. This, and other supernova-produced short gamma radiation bursts could have appeared shorter because the jets from the gamma beams aren't strong enough to escape the star. Astronomers believe this is possible. This would result in shorter jets, both in length and duration. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/J. da SilvaAstronomers have found the shortest gamma-ray burst ever (GRB), which was caused by the implosion a massive star. Astronomers used the international Gemini Observatory program of NSF’s NOIRLab to identify the source of the 0.6 second flurry of Gamma Rays. It was a supernova explosion in distant galaxies. GRBs caused by supernovae are usually more than twice as long, which suggests that some short GRBs might actually be imposterssupernova-produced GRBs in disguise.Scientists are still trying to figure out what causes the fleeting Gamma-ray Bursts (GRBs), which are some of the most bright and energetic events in the universe. GRBs are divided into two main categories by astronomers based on the duration of their existence. GRBs that last less than 2 seconds burst into life and are believed to be the result of the merger of binary neutron star. Longer GRBs are those that last for longer and are associated with supernova explosions due to the implosion of massive stars. The recent discovery of the longest-ever GRB during a supernova proves that GRBs don’t fit into the boxes that astronomers have made for them.Toms Ahumada is a Ph.D candidate at the University of Maryland, and an astronomer at NASA’s Goddard Space Flight Center. "This discovery represents a short gammaray emission caused by supernovas during the collapse of massive stars." It lasted only 0.6 seconds, so it is a gammaray burst that could be successful or failed.According to the team, this GRB and other supernova-related GRBs appear short because the jets from supernova's poles don't have enough strength to escape the star. This is why almost all collapsing stars produce GRBs but their jets are so weak that they don’t produce any.This discovery may also help to solve an astronomical mystery. Type Ic-BL is the type of supernova that long GRBs are linked to. Astronomers see many more supernovae than long GRBs. The discovery of the supernova's shortest GRB suggests that some supernova-caused GRBs may be masquerading as GRBs created by neutron star mergers. They are not being counted as supernovae.Astronomers in Hawaii used the Gemini North telescope to identify the source of the unusually short bursts of gamma radiations. Supernova explosions are known to produce a long gamma ray burst (GRB). Astronomers believe that these GRBs and other GRBs produced by supernovas may be disguised as GRBs. These GRBs appear shorter because of the fact that their gamma radiation jets are not strong enough to escape the collapsing star. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/J. da Silva/NASA/Goddard Space Flight CenterAhumada stated, "Our discovery suggests, since we observe more of these supernovae that long gamma ray bursts," that most collapsing stellites fail to produce a GRB Jet that breaks through the outer shell of the collapsing stellium. We believe this event was a fizzle and that it was very close to not occurring at all.Thanks to the imaging capabilities provided by the Gemini Multi-Object Spectrograph at Gemini North in Hawaiii, the team was able determine that the GRB identified as GRB200826Aoriginated after a supernova explosion. Gemini North was used by the researchers to take images of the GRB's host galaxies. These were taken 45 days and 80 days after the GRB's detection by a network that included NASA's Fermi Gamma-ray Space Telescope. Gemini's observations enabled the team to see the sign of a supernova despite its location in a galaxy that is 6.6 billion light years away.Ahumada said, "This was a difficult endeavor as we had to separate the light from an already faint galaxy and the light from a supernova." "Gemini, the only ground-based telescope capable of performing follow-up observations such as this with a flexible schedule that allows us to squeeze in our observations," said Ahumada.This shows that judging GRBs solely based on their duration is not a good approach. Additional observations are required to determine the cause of a GRB.Ahumada said, "Initially we were looking for merging neutron star, which are thought produce short gamma ray bursts." "We discovered GRB200826A and realized that the burst could have been caused by a supernova collapsing star. This was quite a surprise."Martin Still, Gemini Program officer at NSF, stated that "The Gemini observatories continue shed new light on how these amazing explosions occur across the distant universe." Gemini will continue to lead the way in following up on these amazing cosmic events with dedicated instrumentation that will be available over the next ten years.Explore more Shocks from a distant Gamma-ray BurstMore information: Discovery and confirmation of the shortest gamma ray burst from a collapsar, arXiv:2105.05067 [astro-ph]