Astronomers Left Puzzled After Detecting an Unusual, Repeating Signal Emitted Deep in the Galactic Plane

In the ever-expanding cosmos, astronomers are constantly reminded that the universe does not run out of surprises. One such mystery has now emerged from deep within our galaxy, shaking up conventional astrophysics and igniting global curiosity. At the same time, terrestrial complications from satellites to rogue radio signals continue to threaten these cosmic discoveries, as per Nature. But what if those interference signals could be analysed?

Enter ASKAP J1832- 0911, a stunning celestial object identified using the ASKAP radio telescope on Wajarri Country in Australia. This weird signal, a repeating long-period transient (LPT), emits powerful bursts of radio waves every 44.2 minutes, a periodicity unlike anything normally seen in the cosmos. Discovered by a team from Australia’s national science agency, CSIRO, the object has challenged nearly every known model of stellar behavior. Dr. Ziteng (Andy) Wang, lead author, remarked, "Long-period transients are a recently identified class of cosmic objects that emit bright flashes of radio waves every few minutes to several hours. This is much longer than the rapid pulses we typically detect from dead stars such as pulsars…Our discovery opens up a new window into the study of these puzzling sources. But it also deepens the mystery: the object we found doesn’t resemble any known type of star or system in our galaxy – or beyond," as per IFL Science.

What makes it even more surprising is the multi-wavelength nature of the signal. While ASKAP was detecting the repeating radio pulses, NASA’s Chandra X-ray Observatory, purely by chance, was looking at the same part of the sky and spotted coinciding bursts of high-energy X-rays. Wang added, "This suggests something dramatic happened shortly before we first detected it – something powerful enough to suddenly switch the object 'on' Then, in February 2024, ASKAPJ1832 became extremely active. After a quieter period in January, the source brightened dramatically. Fewer than 30 objects in the sky have ever reached such brightness in radio waves," as per IFL Science.

However, despite the theories ranging from old magnetars to magnetized white dwarf binaries, none fully explain ASKAP J1832- 0911’s peculiar behavior. Wang remarked, "This object is unlike anything we have seen before…ASKAP J1831-0911 could be a magnetar (the core of a dead star with powerful magnetic fields), or it could be a pair of stars in a binary system where one of the two is a highly magnetised white dwarf (a low-mass star at the end of its evolution)...However, even those theories do not fully explain what we are observing. This discovery could indicate a new type of physics or new models of stellar evolution," as per IFL Science.

But a breakthrough by astronomers Jonathan Pober and Ph.D. student Jade Ducharme might offer a solution. They tracked a puzzling TV signal picked up by the Murchison Widefield Array (MWA) in Australia, located in a protected radio quiet zone, and discovered it had been bouncing off a commercial airplane mid-flight at 38,400 feet, as per Space. Using beamforming and near-field correction techniques, they identified the signal as belonging to Australian Channel 7, reflected from the airplane’s hull. This not only solved the signal’s origin but also demonstrated a method to model and potentially subtract such interference from astronomical data.