Astronomers have just discovered what may be the most powerful flash of light ever seen.
so called gamma-ray burstthe most energetic type of electromagnetic explosion in existence UniverseIt was first spotted by telescopes on Sunday (October 9).
Gamma-ray bursts, accidentally detected by US military satellites in the 1960s, were likely produced when stars They explode at the end of their life before collapsing black holesor when there is a super dense stellar remnant known as neutron stars Clash. Within seconds, these explosions release a similar amount of energy the sun It will be issued during its 10 billion year life.
The flash detected on Sunday was the most powerful of all, releasing 18 TeV of energy. Scientists are still analyzing the measurements, but if the results are confirmed, the gamma-ray burst would be the first ever gamma-ray burst to carry more than 10 TeV of energy.
Related: One study found that gamma-ray bursts can be much rarer than we thought
At first, the power of the flash confused astronomers; They thought it must have been produced from a relatively close source. They also initially believed that the energy came from X-rays, not gamma rays. Subsequent analysis of the signal confirmed that it was indeed a gamma-ray burst coming from a source of about 2.4 billion. light years distant. While the gamma-ray burst isn’t exactly close, it’s still the closest of all.
Although the gamma-ray explosion was at a safe distance from Earth, a much closer explosion would be catastrophic for our planet. Such an energetic flash for thousands of light years from a land It would strip the planet of its protective ozone layer and could cause a mass extinction. In fact, scientists believe that one of the largest mass extinction events in Earth’s history – the Ordovician extinction, which occurred 450 million years ago – may have caused such an explosion, according to NASA (Opens in a new tab).
Although the recently observed gamma-ray burst, dubbed GRB221009A, appeared 20 times closer to Earth than the average gamma-ray burst, it was still far enough away to cause more excitement than concern.
“This is a very exciting event indeed!” said Gemma Anderson, an astronomer at Curtin University in Australia who studies similar phenomena ScienceAlert (Opens in a new tab). “This event is very close, but also very active, which means that the radio light, the X-rays and the gamma rays it produces are very bright and therefore easy to observe. So we can study gamma-ray bursts with many large and small telescopes around the world and collect very complete datasets because they first ignite and then vanish. “
Gamma-ray bursts are of two types. Short gamma-ray bursts are rare and last no more than two seconds. These explosions make up about 30% of all these events and are believed to be caused by the collision of neutron stars. The other type, long gamma-ray bursts, can last up to several minutes and are likely to produce hypernoveStarbursts 100 times brighter than supernovaMost massive stars die after their cores run out of hydrogen fuel.
Astronomers often see the afterglow of these bursts coming from the electrons activated by the explosion. GRB221009A appears to be a long gamma-ray burst, but astronomers still don’t know why it originated.
“It’s still too early to tell,” Anderson told ScienceAlert. “The light from the supernova below will take days to shine. However, due to the long duration of the gamma-ray burst, it could be a very powerful type of supernova. “
Telescopes around the world (and in Earth’s orbit) are now pointing towards dust galaxy from which the lightning came. They will try to observe the light generated by the explosion in as many wavelengths as possible to get a more complete picture of its origin.
“When you are dealing with cosmic explosions that explode stellar remnants close to the speed of light, leaving behind a black hole, you are looking at physics in the most extreme environments that are impossible to recreate on Earth,” Anderson told ScienceAlert. “We don’t fully understand this process yet. Such a close eruption means we can collect high quality data to study and understand how such eruptions occur. “
The notes were first published in astrological telegram (Opens in a new tab) Sunday 9 October.
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