An object 500 million light-years away from Earth has been sending signals once every 16 days, baffling scientists. Such signals, called Fast Radio Bursts (FRB), have been detected before. In fact, scientists already know about 100 types of FRBs. But what makes this specific FRB special is that it is the only one to have shown a consistent tempo. The FRB pattern was found in the data generated by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope in British Columbia.
The signal, named FRB 180916.J0158+65, is one of the few FRBs that has been traced back to a galaxy. It is located in a star-forming region on the outskirts of a spiral galaxy. As such, experts have ruled out the possibility of a supermassive black hole. However, a stellar-mass black hole is still a possibility.
“The single constraint on the orbital period still allows several orders of magnitude range in companion mass amongst known stellar-mass compact object binaries: from so-called ‘black widow’ binary systems, consisting of a low-mass star and a powerful millisecond pulsar whose wind ablates the companion (albeit typically with few-hour orbital periods), to massive O/B stars with highly eccentric companion pulsar orbits,” the researchers said in the paper (Science Alert).
FRB 180916.J0158+65 was one of the eight FRBs that CHIME discovered last year. However, nothing about the FRB stood out as special initially. But as the CHIME experiment continued with observations, a pattern started to emerge — the FRB was repeating the signals on a 16.35-day cycle. The nature of the repetition provides some major clues as to what the object sending the signal could be. For instance, it could indicate that the object is something that is in an orbit and only faces the Earth during a short window of time.
Some have speculated as to whether the signal could be of alien origin. However, experts have dismissed such theories since such a communication method would not be used by a species capable of having advanced intelligence. “If it were an alien beacon I would think it would emit more quickly because a 16-day period is not efficient for communication. Imagine getting one signal every 16 days — it would take forever to get a message,” Leon Oostrum at the Netherlands Institute for Radio Astronomy told New Scientist (New York Post).
Last year, a student from Swinburne University, Australia, created an automated system that uses AI to detect and capture FRBs in real-time. The student, Wael Farah, is the first person to have identified FRBs through such a method. By the time the results of his research were published, Farah had already discovered five bursts, including one of the most energetic signals ever detected up to that time.
Farah’s interest in FRBs came after he realized that they could be used to study matter around and between the galaxies. Such matter would be impossible to see under normal circumstances. “It is fascinating to discover that a signal that travelled halfway through the universe, reaching our telescope after a journey of a few billion years, exhibits complex structure, like peaks separated by less than a millisecond,” he said to Phys.Org.
For his experiment, Farah trained the on-site computer at Canberra’s Molonglo Radio Observatory in such a way that it became capable of identifying the signs of an FRB and would respond immediately by capturing its details. The high-quality data allowed researchers at Swinburne to study the structure with greater precision.