The meaning of this unusual signal that we have received from beyond the galaxy is still a mystery to astronomers.

They are aware of the source of the signals. ASKAP J193505.1+214841.0, or simply ASKAP J1935+2148, is a neutron star that is situated 15,820 light-years from Earth on the Milky Way’s plane.

However, the signals themselves are unlike anything we have ever seen. The star experiences powerful pulses, faint pulses, and no pulses at all during different times.

A group led by Australian astrophysicist Manisha Caleb of the University of Sydney claims to know what we don’t know about why. Since our models of neutron star evolution are currently far from comprehensive, the odd item presents an intriguing challenge.

What remains of a star that dies within a specific mass range—between 8 and 30 times the mass of the Sun—is called a neutron star. A supernova explosion results from the outer material of the star being launched into space.

Under the influence of gravity, the star’s remaining core collapses to form an ultra-dense object that can contain up to 2.3 times the mass of the Sun in a sphere of 20 kilometers (12 miles) across.

The resulting neutron star can subsequently take many different forms. The base neutron star is one example; it does nothing but sit around. The pulsar, for example, flashes like a cosmic signal as it rotates, sweeping beams of radio radiation from its poles.

And then there’s the magnetar, a neutron star with an incredibly strong magnetic field that movements and explodes when the star’s gravity is battling the magnetic field’s outward force.

Additionally, there may occasionally be a crossover between the different types of neutron stars, indicating that they may be at distinct phases of evolution. However, the behavior of neutron stars, magnetars, and pulsars is generally predictable.

The behavior of ASKAP J1935+2148 is not consistent with that of a known type of neutron star. It was first discovered by coincidence while observing another target. Subsequent observations were conducted with the Australian Square Kilometre Array Pathfinder (ASKAP) and the South African radio telescope MeerKAT.

Additionally, the researchers examined earlier ASKAP data that covered the same area of the sky.

They discovered that ASKAP J1935+2148 pulses at a regular interval of 53.8 minutes, but that appeared to be the sole feature of its pulsations that was typical. They discovered that one pulse mode had highly linear polarization and was incredibly bright. However, after a while, there would be no more detectable pulsations at all.

At last, the star was found to be pulsating again, but with circularly polarized light and 26 times fainter than in its previous outstanding phase.

A number of unusual objects have been observed spitting out recurrent signals in the southern sky in recent years. They may be connected even though they don’t all behave in the same manner.

An object close to the galactic center known as GLEAM-X J162759.5-523504.3 was observed to produce strangely brilliant flashes for a short amount of time before becoming quiet once more. Every 22 minutes, GPM J1839-10 was observed to release five-minute radio wave bursts, matching the behavior of an oddly slow pulsar. And with a period of 77 minutes, GCRT J1745-3009 is a pulsating object close to the galactic center.

Although the nature of any of these objects is unknown, neutron stars seem to be the most likely candidate. In addition, Caleb and her colleagues propose that ASKAP J1935+2148 might serve as a kind of link between the various states.

The objects appear to belong to a new type of magnetars, maybe in the process of evolving into pulsars, based on the variances in their pulsation modes, which are most likely related to changes and processes occurring in the magnetic field.

“ASKAP J1935+2148 is probably part of an older population of magnetars with long spin periods and low X-ray luminosities, but magnetized enough to be able to produce coherent radio emission,” the authors of the report wrote.

“It is important that we probe this hitherto unexplored region of the neutron-star parameter space to get a complete picture of the evolution of neutron stars, and this may [be] an important source to do so.”