Astronomers have discovered a mysterious object emitting a radio wave beam that pulsed every 20 minutes. According to The Guardian, the team behind the discovery believes the object could be a new class of slowly rotating neutron star with an ultra-powerful magnetic field.
The repeating signals were detected during the first three months of 2018, but then disappeared, suggesting they were linked to a dramatic, one-off event, such as a starquake.
“It was kind of spooky for an astronomer because there’s nothing known in the sky that does that,” said Natasha Hurley-Walker, from the Curtin University node of the International Centre for Radio Astronomy Research, who led the team that made the discovery.
Despite the unusual nature of the signal, the team believes the source is likely to be a spinning object rather than a technologically advanced civilization reaching out across the cosmos. “It’s definitely not aliens,” said Hurley-Walker.
The team briefly considered this possibility but ruled it out after determining that the signal – one of the brightest radio sources in the sky – was detectable across a broad spectrum of frequencies, meaning that an immense amount of energy would have been required to produce it.
The object, believed to be about 4,000 light years away in the plane of the Milky Way, also matches a predicted astronomical object called an “ultra-long period magnetar,” a class of neutron star with the most powerful magnetic field of any known object in the universe.
“It’s a type of slowly spinning neutron star that has been predicted to exist, theoretically. But nobody expected to directly detect one like this because we didn’t expect them to be so bright,” said Hurley-Walker.
A neutron star is the dark, dense remnant left behind after a supermassive star casts off its outer material in a supernova and undergoes gravitational collapse. Reduced to the size of a small city, neutron stars initially spin incredibly quickly.