The incredibly dense remnants of a dead star, known as neutron stars, usually rotate at extremely high speeds, taking just seconds or even milliseconds to complete one full round on their axis. This law is broken by the neutron star, which was just found by a global team of astronomers.
Scientists have found what they believe to be a neutron star spinning at a speed never before seen in any of the more than 3,000 radio-emitting neutron stars studied. It releases radio waves every 54 minutes, a slow interval.
Ben Stappers, Professor of Astrophysics at The University of Manchester, said: “In the study of radio-emitting neutron stars, we are used to extremes, but this discovery of a compact star spinning so slowly and still emitting radio waves was unexpected. It demonstrates that pushing the boundaries of our search space with this new generation of radio telescopes will reveal surprises that challenge our understanding.”
The scientists discovered an unexpected radio signal from the star object that traveled 16,000 light years to Earth. It appears to be a neutron star based on the type of radio emission and the speed at which the spin period changes. It’s still possible that it’s an isolated white dwarf with a potent magnetic field, according to the experts. However, the neutron star theory appears more likely given the lack of additional nearby highly magnetic white dwarfs.
Either possibility promises to offer important insights into the physics of these extreme things, but more investigation is needed to confirm the object’s nature.
The results may cause scientists to reevaluate their long-held theories about neutron stars and white dwarfs, including how they produce radio waves and the makeup of their populations throughout the Milky Way galaxy.
Dr. Kaustubh Rajwade, an Astronomer at the University of Oxford, said: “This discovery relied on the combination of the complementary capabilities of ASKAP and MeerKAT telescopes as well as the ability to search for these objects on timescales of minutes while studying how their emission changes from second to second! Such synergies allow us to shed new light on how these compact objects evolve.”
The discovery was made using CSIRO’s ASKAP radio telescope in Wajarri Yamaji Country in Western Australia.
Lead author Dr Manisha Caleb from the University of Sydney Institute for Astronomy said: “What is intriguing is how this object displays three distinct emission states, each with properties entirely dissimilar from the others. The MeerKAT radio telescope in South Africa was crucial in distinguishing between these states. If the signals didn’t arise from the same point in the sky, we would not have believed it to be the same object producing these different signals.”
Journal Reference:
- Caleb, M., Lenc, E., Kaplan, D.L. et al. An emission-state-switching radio transient with 54 minutes. Nat Astron (2024). DOI: 10.1038/s41550-024-02277-w
