Astronomers have determined that at a distance of 2.4 billion light-years from us, one of the most powerful explosions in the universe occurred.
The event, first detected on October 9, was so bright that it was initially mistaken for an incident closer to Earth.
Originally named Swift J1913.1+1946, it was thought to be a brief burst of X-rays from a not too distant source. It was only through further analysis that astronomers discovered the true nature of the burst.
It turned out to be a gamma-ray blast, one of the most powerful explosions in the universe, now renamed GRB221009A, writes ScienceAlert. A bright gamma-ray burst was the most energetic ever detected, its power reaches 18 teraelectronvolts.
“This event is so close and so powerful! This means that the radio, optical, X-ray and gamma radiation that it produces is extremely bright, so it is easy to observe. And collect full datasets as it first gets brighter and then disappears,” says astronomer and transient specialist Gemma Anderson of the Curtin University International Center for Radio Astronomy Research (ICRAR) in Australia.
Gamma rays are the most active form of light in the universe. It results from the radioactive decay of atomic nuclei. A gamma-ray burst is a huge event that releases as much energy as the sun could produce in 10 billion years. Such bursts mark the end of a star’s life or may be the result of a collision between two neutron stars.
When a star much larger than the Sun runs out of material needed to fuse hydrogen, the external pressure drops and the star collapses under the influence of gravity. The result is a colossal explosion (supernova), which ejects external material into space. The nucleus collapses into a neutron star or black hole.
Different types of gamma-ray bursts represent different types of explosions. But what exactly caused GRB221009A is still unclear.
It is known for sure that the explosion occurred in a galaxy rich in dust, and that it was very powerful. So far, scientists do not fully understand this process so they tune their telescopes to conduct more observations of this region of the sky in order to determine the causes of the explosion by observing the afterglow at as many wavelengths as possible.
A different perspective
The official speed of light is somewhere around 300,000 kilometers per second. It is difficult to accurately measure it, but even from existing instruments it is clear that different wavelengths have different speeds. At the same time, the greater the difference in wavelength, the greater the difference in speed.
Gamma rays from the frequency table are very far from visible photons. At the same time, they have pronounced corpuscular properties, they are not even completely radiation, but rather a stream of particles, which is much slower than visible photons. At a distance of 1000 kilometers, this difference in speed will be very small, but at a distance of 2.4 billion light years, the difference will be significant.
And if we take into account that at a distance of 2.4 billion light years, space is definitely not empty – there are gas nebulae, dark matter, gravitational lenses, and much more, then the difference in the time it takes for different frequencies to travel such a colossal distance will be huge, amounting to thousands years. Nevertheless, scientists manage to observe a visual supernova and its gamma radiation almost simultaneously, which is very strange.
Furthermore, the nearest galaxy to us is called the Andromeda Nebula. Its distance is 2.4 million light years. This is 1000 times closer than the hypothetical source of the GRB221009A burst. This means that in a sphere with a radius of 2.4 billion light years there are quite a lot of galaxies, only along one line there are about a thousand of them. And there are at least 100 or more billion stars in each galaxy, although there are over a trillion in large galaxies.
With such a density of stars around, supernovae (in a sphere with a radius of 2.4 billion light years) appear if not every hour, then every day, and many explode much closer than the GRB221009A. Black holes the size of galactic nuclei even collide there, after which such a gamma-ray wind rises in space that blows away the atmosphere from the planets. But somehow we don’t see it and then somewhere, hell knows how far something exploded – and everyone saw it.
In general, this whole scenario about a gamma-ray burst in some far, far away galaxy could be in the science fiction sphere of influence, designed to somehow cover the topic with the growth of gamma radiation falling on Earth from an incomprehensible source.
