Discovery of the Milky Way as astronomers spot a ‘ghostly’ rotating object like never before | Science and technology news
Astronomers have discovered a mysterious spinning object in the Milky Way that is emitting a beam of radio waves every 18 minutes – and unlike anything seen before.
The object has been observed to emit a huge burst of radio energy for a full minute every 18 minutes.
Researchers estimate it’s about 4,000 light-years away and could be a new class of slowly rotating neutron stars with an ultra-strong magnetic field that can be detected by radio telescopes.
The observation is known as a radio transient, which refers to an object periodically emitting short bursts of radio signals, as if turning on and off in space.
“For an astronomer, it was kind of scary because nothing in the sky is known to do that,” said Natasha Hurley-Walker of the International Center for Radio Astronomy Research at Curtin University, who led the team that made the discovery.
While the occurrences have been observed before — typically as very rapid events that turn on and off within seconds or milliseconds, or as longer bursts that last for days — no radio transients have previously been detected, appearing and disappearing over a few hours, he said Mrs. Hurley-Walker .
The team is conducting further investigation to find out what’s causing the bursts of energy, but astronomers think it could be something called a magnetar, which is a special type of “dead” star with an ultra-strong magnetic field.
Ms Hurley-Walker said the prospect of a repeating radio signal in space might lead some to believe it could be an extraterrestrial message, but she said the observations covered a wide range of frequencies – suggesting that they are of natural origin.
First discovered by a student
Former Curtin University student Tyrone O’Doherty first spotted the object by looking at observations of the Milky Way from March 2018 and May 2018, looking for differences.
He said he didn’t expect to make such an intriguing discovery, telling a news conference: “It really feels quite surreal to have found something like this.”
To confirm the discovery, Ms Hurley-Walker searched extensive archives dating back to 2013 to see if the telescope had spotted other activity from the object.
She noted that it had turned on in the first half of 2018, emitting 71 bursts of radio signals from January to March before turning off again. As she and her colleagues found out from their own observations, the pulses came at regular intervals.
“It’s just every 18.18 minutes, like clockwork,” she said.
To unleash more detail, the object needs to be observed when it becomes active again, or similar objects found elsewhere in the Milky Way, Ms Hurley-Walker said.
The team also found that the newly discovered object appears to spin much more slowly than other magnetars, suggesting it has outlived others that typically only last a few thousand years.
But Ms Hurley-Walker said it could also be an entirely new type of cosmic object that caused the flashes of energy.
“Since we didn’t expect this type of radio emission to be possible, the fact that it exists tells us that some kind of extreme physical process must be taking place,” she said.
The researchers explained the findings in a study published this week in the journal Nature.