Scientists have determined the source of the huge glow that swept our solar system.
The discovery could help us understand gamma-ray bursts, the most powerful in the universe.
Earth experiences both light and short bursts of gamma rays regularly on most days. But massive eruptions rarely happen, like the newly examined GRB 200415A, which brings with it more powerful energy from our sun.
The glow appears to have appeared from an unusually strong neutron star known as a magnetic star, according to scientists in new results published in Natural Astronomy.
“Our sun is a very normal star. When it dies, it will grow up and become a giant red star. Then it will collapse into a small compact star called the white dwarf,” said Swibor Razaki of the University of Johannesburg, who led the research.
“But stars that are much larger than the Sun play a different endgame.”
Instead, such stars explode in a supernova and then leave behind a small, compact star known as a neutron star. It’s small – it can be packed into a 12-mile space – yet so dense that a spoonful weighs tons.
These stars are the creators of the most powerful explosions in the universe. Explosions like these affect the phone signal today, but they also represent a way of looking back at the beginnings of the universe, as they arrive with us as messengers of the universe when it was in a much smaller state.
The new search began in April of last year – on the morning of April 15th – when a giant glow swept across Mars. It was picked up by a network of satellites including the International Space Station, which led to the start of the research published today.
When GRB 200415A passed the Earth, it was not the first such explosion to be detected on Earth. But it was unusual in a number of helpful ways, including the fact that it came from much closer to us than usual.
It was also the first giant glow to be captured since the Fermi Gamma-ray Space Telescope launched in 2008. This means that the researchers were able to collect massive amounts of data in 140 milliseconds that lasted, giving them a much better picture than a previous visitor who arrived 16 years ago.
And when the researchers were able to pinpoint the cause, they found it also unusual: It came from a magnetic star. There are only 30 of these known objects in our entire Milky Way galaxy, made up of tens of thousands of neutron stars, and they could be a thousand times magnetic than normal neutron stars.
The galaxy from which the glow came is outside our own Milky Way, but only on a galactic scale. It’s just 11.4 million light-years away.
Because of work in the lead up to the eruption last year, researchers have built a detailed set of predictions about what GRB might look like when it reaches Earth. For example, Professor Razzak predicted 15 years ago that a giant flare would include two explosions, and another closely followed the first, and thus they were able to compare those predictions with their current research.
Scientists hope to be able to find and research it in more detail. This can help explain not only the processes that allow for such powerful explosions, but also use them as ways to make sense of our universe’s story.
Professor Razzaq said in a statement: “Despite the gamma ray bursts from one star, we can discover them from a very early time in the history of the universe. Even going back to a time when the universe was a few hundred million years old.”
“This is at a very early stage in the evolution of the universe. Stars that died at that time … We are now only discovering gamma-ray bursts because light takes time to travel.
“This means that gamma-ray bursts can tell us more about how the universe has expanded and evolved over time.”
