Astronomers Are Stumped By A Mysterious Space Object's Spooky Radio Transmissions
Astronomers are a bit puzzled over a mysterious object 4,000 light years away from Earth that is sending out giant bursts of energy. The object, first spotted in 2018, sent out radio waves three times per hour.
An object located 4,000 light years away, or 24 quadrillion miles, from Earth may seem like a massive distance, but astronomers say that it is actually fairly close in galactic terms. The celestial object is unlike anything they have seen before. Some have suggested it could be a neutron star, or possibly a white dwarf star that has an extremely powerful magnetic field. A study on the discovery has been published in the journal Nature.
In a statement, Natasha Hurley-Walker, lead study author and an astrophysicist at the Curtin University node of the International Centre for Radio Astronomy Research, said, "This object was appearing and disappearing over a few hours during our observations. That was completely unexpected." She continued to say, "It was kind of spooky for an astronomer because there's nothing known in the sky that does that. And it's really quite close to us—about 4,000 light years away. It's in our galactic backyard."
The object was first spotted by doctoral student at Curtin University, Tyrone O'Doherty. He made the observation while using the Murchison Widefield Array telescope in the outback of Western Australia in 2018. The strange object has been observed several times since then, and still continues to perplex astronomers.
"It's exciting that the source I identified last year has turned out to be such a peculiar object," O'Doherty said in a statement. "The MWA's wide field of view and extreme sensitivity are perfect for surveying the entire sky and detecting the unexpected."
Space objects that seemingly turn off and on are referred to as transients. Dr. Gemma Anderson, co-author of the paper and ICRAR astrophysicist, explained that finding something that turns on for a duration of about a minute is what sets this discovery apart from others. Some researchers think that it may be a magnetar, or a neutron star with an extremely strong magnetic field.
Anderson said in a statement, "When studying transients, you're watching the death of a massive star or the activity of the remnants it leaves behind. Slow transients'—like supernovae—might appear over the course of a few days and disappear after a few months." She continued, "Fast transients—like a type of neutron star called a pulsar—flash on and off within milliseconds or seconds."
Magnetars typically flare by the second, but this particular object takes longer. It turns on for about a minute every 18 minutes, which leads researchers to think it could match up with the definition of an ultra-long period magnetar.
"It's a type of slowly spinning neutron star that has been predicted to exist theoretically," Hurley-Walker stated. "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."
Researchers have indicated that they will continue to monitor the celestial object to find out if it turns back on. While they wait, they are continuing to search for similar objects.
Hurley-Walker says that more detections will give astronomers the data needed to tell them if this was a "rare one-off event or a vast new population we'd never noticed before."