Update on mystery flashes from space
A neutron star near a black hole may be transmitting Fast Radio Bursts.
Sorry alien hunters. The latest evidence suggests that Fast Radio Bursts, millisecond long flashes from deep space, are not stray beams designed to power alien spaceships.
According to a study in January’s Nature, the source of a mysterious repeating Fast Radio Burst (FRB) could be a neutron star positioned close to a supermassive black hole.
The first ever recorded FRB was picked up by Australia’s Parkes Radio Telescope in 2001, a five-millisecond flash that blazed with the intensity of 500 million suns. Astronomers spotted the bizarre signal in 2007 while poring through archives.
Since then, many FRBS have been spotted, but that hasn’t solved the mystery of what could cause such immensely powerful bursts. Candidates have included colliding black holes, whiplash from cosmic strings or, as suggested by Harvard astrophysicists Avi Loeb and Manasvi Lingam in 2017, “beams used for powering large light sails” by extragalactic civilisations.
FRB 121102 is the subject of the latest study, “An extreme magneto-ionic environment associated with the fast radio burst source FRB 121102”.
This FRB was first recorded in 2012 by astronomers at the Arecibo Observatory in Puerto Rico. Detected 15 times since, it is the only confirmed repeating FRB. The fact it repeats rules out colliding black holes or neutron stars as the source.
Daniele Michilli of the Netherlands Institute for Radio Astronomy and his colleagues localised the bursts to a starforming region of a dwarf galaxy three billion light-years away.
Precise measurements from the Arecibo telescope – confirmed at the Green Bank Telescope in West Virginia – revealed the radio wave signals had been distorted by passing through an immensely powerful magnetic field.
Their best explanation for the bursts? A neutron star shrouded by an immense magnetic field. That field could be created by a black hole, a highly magnetised wind nebula or a supernova remnant.
Seems like there is still plenty of mystery surrounding FRBS.