Astronomers have detected a series of mysterious and extremely powerful radio waves coming from somewhere within our own galaxy.
It is not the first time the signals, known as Fast Radio Bursts, or FRBs, have been picked up by scientists, but they have never come from within the Milky Way before.
What causes the signals?
The blasts are very short, lasting less than a second, but in some cases can be millions of times more powerful than the Sun.
FRBs are not an entirely new phenomenon, having been first observed in 2007, but scientists have been able to learn more about them on this occasion because they have come from a source relatively close to Earth.
It is now thought that they could be caused by a type of neutron star called a magnetar.
Magnetars are incredibly dense and have a strong magnetic field, and scientists traced x-ray and gamma-ray emissions coming from one at the other side of our galaxy which is thought to have been the cause of these FRBs.
Researchers have documented the new signals in a series of studies published in the scientific journal, Nature, based on observations made from all over the world and in space.
Assistant professor of Physics at the Massachusetts Institute of Technology and lead researcher on one of the FRB studies, Professor Kiyoshi Masui, said: "There's this great mystery as to what would produce these great outbursts of energy, which until now we've seen coming from halfway across the universe.”
He added: "This is the first time we've been able to tie one of these exotic fast radio bursts to a single astrophysical object."
How was the signal measured?
The astronomers used five telescopes to pick up signals from a magnetar at the centre of the galaxy, known as SGR 1935+2154.
X-ray bursts were first observed from the magnetar, which were then followed by brief but brilliant radio flares within several milliseconds of each other. Based on the intensity of the FRB flashes, the astronomers were able to measure the brightness of the magnetar.
One of the co-authors of a study which linked the bursts to magnetars, Pragya Chawla, said:
"We calculated that such an intense burst coming from another galaxy would be indistinguishable from some fast radio bursts, so this really gives weight to the theory suggesting that magnetars could be behind at least some FRBs."