Some somewhat massive, extremely magnetic objects generated enormous amounts of energy around 4,000 years ago. This massive energy beam is aimed at Earth’s current location every 18 minutes. After traveling through space, some of it landed on a radio telescope in Western Australia’s outback in 2018, startling astronomers. Despite some parallels to pulsar signals, the radio wave bursts are unlike anything we have seen before and necessitate a completely novel explanation, which astronomers do not yet have – although aliens have ruled out. Astronomers were astounded in 1967 when they discovered radio signals that appeared and vanished every few seconds or milliseconds, initially dubbed LGMs for Little Green Men.
They have now been identified as pulsars, which are rapidly spinning neutron stars that form because of supernova explosions. In new research published in Nature, student Tyrone O’Doherty and Dr. Natasha Hurley-Walker of Curtin University in Australia had a similar experience identifying the blips from the object now known as (GLEAM-X) J162759.5-523504.3.
The longest pulsar signal lasts 118 seconds, and any larger intervals are thought to be impossible. The cycle of (GLEAM-X) J162759.5-523504.3 is 1,091 seconds, with signals lasting 30-60 seconds. Furthermore, its luminosity is comparable to that of the Crab Nebula’s brightest pulsar. The radiation of J162759.5-523504.3 is strongly linearly polarized (GLEAM-X), indicating the presence of a strong magnetic field.
“During our observations, this object appeared and disappeared over a few hours,” Hurley-Walker said in a statement. “That came as a complete shock. For an astronomer, it seemed a little strange because there is nothing else in the sky that can accomplish that. It is also relatively close to us – roughly 4,000 lightyears away. It’s right here in our galaxy.” Attempts to retrieve the signal of (GLEAM-X) J162759.5-523504.3 were unsuccessful. O’Doherty and Hurley-Walker sifted through years of data from the Murchison Widefield Array (MWA) and discovered 71 pulses across two periods of approximately three months when it was “active.”
Other telescopes have been unable to identify it, which is understandable. Because of the MWA’s unusual combination of sensitivity and wide field, it has discovered a number of objects that other telescopes would only find if they focused on the right spot. This information sparked a search for an explanation for something so strange. The easiest thing was ruling out aliens. Technological signals only cover a small portion of the spectrum, whereas (GLEAM-X) J162759.5-523504.3 covers the entire spectrum.
Producing a signal over such a wide range of frequencies necessitates the release of enormous amounts of energy, which would be wasteful for any civilisation smart enough to do so. A slow pulsar, on the other hand, is not feasible, according to Hurley-Walker. “This would need a magnetic field 100 times stronger than anything else in the cosmos if it were a pulsar,” she said. “It would likewise degrade rapidly.” Faster pulsars have greater power, which is incompatible with the J162759.5-523504.3 bright and slow combination (GLEAM-X) displays.
It also studied whether two objects in an extended orbit could produce energy bursts as they approached each other. Hurley-Walker told IFLScience that she does not rule out the possibility, but that extensive consultation has failed to generate a viable model.
As a result, the team is leaning toward a magnetar whose massive magnetic field has “become twisted and convoluted,” according to Hurley-Walker. “It produces the burst of energy we perceive when it untwists before piling up again.” J162759.5-523504.3 is 2.5 degrees off the galactic plane (GLEAM-X). Its distance is computed using dispersion, which accounts for the fact that longer objects slow down more when passing through interstellar material. Hurley-Walker told IFLScience that nothing has been found that matches this position, although the area is congested because it is so close to the galactic plane. Hurley-Walker congratulated O’Doherty for opting for the galactic plane over easier but less promising portions of the sky during a press conference.
