We may finally know where fast radio bursts (FRBs) come from. These mysterious flashes of radio waves from space have now been spotted in our galaxy and appear to be connected to neutron stars called magnetars that have powerful magnetic fields.
FRBs are powerful blasts of radio waves that last just a few milliseconds. Suggested origins range from聽starquakes to alien spaceships, but since they were first discovered in 2007, astronomers have been unable to figure out exactly what causes them.
Now, two discoveries hint at an explanation. is a finding that an extragalactic FRB spotted in 2017 appears to have occurred at the same location as an earlier gamma ray burst. Some gamma ray bursts, including this one, are thought to be caused by supernovae that leave behind magnetars after they explode.
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鈥淲e really hope to see a lot more bursts from this FRB so we can be sure it鈥檚 coming from the same place as this gamma ray burst,鈥� says Bing Zhang at the University of Nevada Las Vegas, who was part of the team that found this match-up. If it is, that would be hard evidence that FRBs can be produced by magnetars, which has long been one of the leading ideas for their origin.
聽of this came from the CHIME telescope collaboration, which spotted a strangely bright, quick burst on 28 April 鈥� the first from within the Milky Way. 鈥淭his is a fast radio burst that is coming from within our galaxy,鈥� says CHIME team member Paul Scholz at the University of Toronto in Canada. 鈥淲hether it is the same beast as an extragalactic FRB is not certain yet, but it鈥檚 a possibility.鈥�
That burst came from a known magnetar within our galaxy called SGR 1935+2154. Other astronomical observatories found bursts of gamma rays and X-rays coming from the same spot at the same time, which we have never been able to observe from any other FRBs because they are all too far away.
鈥淭his is an unquestionable breakthrough,鈥� says Jason Hessels at the Netherlands Institute for Radio Astronomy. 鈥淚t directly shows that neutron stars can produce radio bursts鈥� pretty close to what we鈥檝e seen from extragalactic FRBs.鈥�
If we placed this burst at the distance of the closest FRB we know of beyond our galaxy, it is bright enough that we might still be able to spot it, Scholz says. This makes it possible that it is similar to FRBs beyond our galaxy 鈥� and if it is, it will provide a priceless laboratory to study the mechanism behind FRBs from close up.
鈥淎t least some FRBs should come from magnetars 鈥� this is firm now,鈥� says Zhang. 鈥淚n the past it was a guess, even if it was the best guess, but now it鈥檚 a fact.鈥�
Nevertheless, some questions remain unanswered. For example, while the burst found by CHIME may be the brightest seen within our galaxy, some FRBs are orders of magnitude brighter, and it isn鈥檛 clear whether a magnetar could provide enough energy to make such a bright burst.
鈥淚t鈥檚 very preliminary at this point, and there鈥檚 a lot more to be investigated, but it鈥檚 obviously an extremely tantalising and exciting connection.鈥� says Scholz.
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