Astronomers have revealed that a telescope in Canada has picked up mysterious repeating signals emanating from a galaxy 1.5 billion light years away, BBC reported on Wednesday.
The CHIME observatory in British Columbia detected 13 fast radio bursts, known as FRBs, and among them was a very unusual repeating signal that scientists say originated from the same source. Such an event was reported only once before by a different telescope. The signal repeated six times, researchers wrote in two new papers published in the Nature journal.
Scientists do not know what causes fast radio bursts, though they have been speculated to be caused by a neutron star with a very strong magnetic field that is spinning very rapidly, two neutron stars colliding, or by some type of alien spacecraft. There is little evidence of where they might be coming from, The Independent reported. The flashes only last for a millisecond but when they originate they have the same amount of energy the sun takes 12 months to produce.
The two sets of repeating bursts would help scientists understand what distinguishes repeating signals from single bursts, their source, and also watch out for future radio bursts.
“Whatever the source of these radio waves is, it is interesting to see how wide a range of frequencies it can produce,” said Arun Naidu of McGill University, who was also part of the team of researchers who studied the signals. “There are some models where intrinsically the source can’t produce anything below a certain frequency.”
Of the 13 signals that were picked up, at least seven were recorded at 400 MHz – the lowest frequency of any such radio burst discovered till date. That suggests there might be even more of them, too low to be picked up by telescopes.
“[We now know] the sources can produce low-frequency radio waves and those low-frequency waves can escape their environment, and are not too scattered to be detected by the time they reach the earth,” The Independent quoted researcher Tom Landecker as saying. “That tells us something about the environments and the sources. We have not solved the problem, but it’s several more pieces in the puzzle.”