Astronomers Stunned by the Mysterious Existence of an Unkillable ‘Zombie Star’

A collapsed star situated roughly 13,000 light years away is so peculiar that the scientists who uncovered it assert it shouldn’t be present.

Initially identified in January 2024 by the ASKAP radio telescope located in Western Australia, it is likely a type of pulsar that has not been previously observed.

When supermassive stars approach the conclusion of their existence and detonate in a supernova, the remnants create a super-dense entity referred to as a neutron star. Pulsars are neutron stars that revolve swiftly, emitting radio waves from their magnetic poles as they spin. Most pulsars rotate at velocities exceeding one revolution per second, allowing us to perceive a pulse at the identical frequency, each time a radio beam is directed towards us.

However, in recent years, astronomers have started to identify compact objects that transmit pulses of radio waves at a considerably slower tempo. This has puzzled researchers, who believed that radio wave bursts should halt once the rotation becomes slower than a minute for each spin.

These slowly spinning entities are recognized as long-period radio transients. Last year, a team guided by Manisha Caleb at the University of Sydney, Australia, communicated the discovery of a transient with a duration of 54 minutes.

Now, Caleb and her team affirm that a novel object they uncovered a year earlier, designated ASKAP J1839-0756, is rotating at a newly established sluggish rate of 6.45 hours per rotation.

This is also the first transient ever identified with an interpulse: a fainter pulse occurring halfway between the primary pulses, emanating from the opposite magnetic pole.

Initially, the team speculated that ASKAP J1839-0756 could be a white dwarf, a smaller star resembling our sun that has expired. “Yet we have never observed a solitary white dwarf emitting radio pulses, and our analysis indicates that it is too massive to be an isolated white dwarf based on the pulse characteristics,” explains Joshua Lee, a member of the team at the University of Sydney.

Subsequently, the group considered it might be a magnetar, a neutron star possessing an enormous magnetic field – potentially up to 10 trillion times more potent than the strongest MRI machines available on Earth.

A magnetar featuring a similar rotational period of 6.67 hours has previously been discovered; however, thus far, it has only emitted X-rays, not radio signals.

Caleb points out that if the star is indeed an isolated magnetar, it would be the first to emit in the radio wave spectrum with such a slow period.

“This newest entity is fundamentally altering our understanding of radio emission mechanisms from neutron stars over the past six decades,” claims Caleb. “It is undoubtedly one of the most peculiar objects in recent history, as we did not believe these phenomena existed. But now we are uncovering them. Should it be a magnetar, it’s certainly distinct among the neutron star population.”

She mentions that the notion that pulsars stop emitting radio waves when their rotation becomes excessively slow must be reevaluated.

“We have been observing objects recently that appear to transcend this cessation threshold, yet they are still emitting in the radio [frequency],” remarks Caleb. “Thus they resemble zombie stars where one would not anticipate them to be active, but they are indeed active, continuously pulsing.”

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