A team of astronomers mapping radio waves in the universe has discovered something “kind of spooky” spinning around in space that converts magnetic energy to radio waves much more effectively than anything they’ve ever witnessed before.
In a press release on Wednesday, researchers at the International Center for Radio Astronomy Research (ICRAR) said the strange object is 4,000 light-years away from Earth and releases a giant burst of energy three times an hour.
Extremely bright and smaller than the Sun, the object, known as GLEAM-X J162759.5-523504.3, emits highly-polarized radio waves, which suggests that it has an extremely strong magnetic field.
“Spinning around in space, the strange object sends out a beam of radiation that crosses our line of sight, and for a minute in every 20, is one of the brightest radio sources in the sky,” researchers said.
Astronomers believe the new discovery may be a neutron star (the collapsed core of a massive supergiant star that has run out of fuel) or a white dwarf (stars that have burned up all of the hydrogen they previously used as nuclear fuel)—and has an extremely powerful magnetic field.
It was first discovered by Curtin University honors student Tyrone O’Doherty who used the Murchison Widefield Array (MWA), a low-frequency radio telescope in Western Australia.
O’Doherty utilized a new technique he has developed to unearth the discovery.
“It’s exciting that the source I identified last year has turned out to be such a peculiar object,” O’Doherty said. “The MWA’s wide field of view and extreme sensitivity are perfect for surveying the entire sky and detecting the unexpected.”
Astrophysicist Natasha Hurley-Walker, who led the team that made the discovery said, “This object was appearing and disappearing over a few hours during our observations.”
“That was completely unexpected. It was kind of spooky for an astronomer because there’s nothing known in the sky that does that,” Hurley-Walker said, adding that the object is “in our galactic backyard.”
Objects that “turn on and off” in space are relatively common and referred to as “transients” by scientists.
“Slow transients” such as supernovae, can appear within a few days and disappear after a few months, while “fast transients” such as the pulsar neutron star “flash on and off” multiple times within milliseconds.
However, transients in between those two speeds are extremely rare.
ICRAR-Curtin astrophysicist and co-author Gemma Anderson said that “when studying transients, you’re watching the death of a massive star or the activity of the remnants it leaves behind” but that finding a transient that turned on for a minute was “really weird.”
Hurley-Walker said researchers believe the object might be something known as an “ultra-long period magnetar,” a predicted astrophysical object that it was previously thought was impossible to detect.
“It’s a type of slowly spinning neutron star that has been predicted to exist theoretically,” she said. “But nobody expected to directly detect one like this because we didn’t expect them to be so bright. Somehow it’s converting magnetic energy to radio waves much more effectively than anything we’ve seen before.”
Astronomers are monitoring the newly-discovered object to see if it switches “back on” again and will use scientific telescopes across the Southern Hemisphere as well as those in orbit to get a good look at it.
In the meantime, researchers will continue to look for more unusual objects in the archives of the Murchison Widefield Array telescope.
“More detections will tell astronomers whether this was a rare one-off event or a vast new population we’d never noticed before,” Hurley-Walker said.