Unprecedented Discoveries: Radio Signals from a Dormant Star

Monday - April 8 2024, 23:41 UTC - 9 months ago

In 2024, researchers used CSIRO's Murriyang telescope to make an unprecedented discovery: unusual radio pulses coming from magnetar XTE J1810-197, the closest known magnetar to Earth at 8,000 light years away. This magnetar emits circularly polarized light, suggesting complex interactions at its surface, and a superheated plasma acting as a polarizing filter. The discovery was made possible by CSIRO's cutting-edge receiver, and studying magnetars can provide insights into extreme and unusual phenomena in the Universe.

On April 8, 2024, researchers using CSIRO's Parkes radio telescope in Murriyang made an unprecedented discovery: unusual radio pulses coming from a previously dormant star with a powerful magnetic field. This magnetar, known as XTE J1810-197, is one of the few known to emit radio signals and is also the closest magnetar to Earth at a distance of about 8,000 light years.

Magnetars are a type of neutron star, an incredibly dense and compact object with a strong magnetic field. They are the strongest known magnets in the Universe. While most magnetars emit polarized light, the light emitted by XTE J1810-197 is circularly polarized, meaning it appears to spiral as it moves through space. This behavior is unexpected and completely unprecedented.

Dr. Marcus Lower, a postdoctoral fellow at CSIRO, led the research and described the results as unexpected and unprecedented. According to Dr. Lower, the radio signals from this magnetar emit enormous amounts of rapidly changing circular polarization, something that has never been seen before in other magnetars. This discovery challenges previous theoretical explanations about the complexity of interactions at the surface of the star.

Co-author of the study, Dr. Manisha Caleb from the University of Sydney, explains that studying magnetars can provide valuable insights into the physics of intense magnetic fields and the unique environments they create. The circularly polarized light emitted by XTE J1810-197 suggests that there is a superheated plasma above the star's magnetic pole, acting as a polarizing filter. This new finding will require further investigation to determine exactly how the plasma is causing this behavior.

The team's discovery was made possible thanks to CSIRO's cutting-edge ultra-wide bandwidth receiver, designed by their world-leading engineers for radio astronomy applications. This receiver is highly sensitive to changes in brightness and polarization and has allowed for more precise measurements of XTE J1810-197's radio emissions.

The study of magnetars, including XTE J1810-197, can provide valuable insights into a range of extreme and unusual phenomena in the Universe, such as plasma dynamics and bursts of X-rays and gamma-rays. Additionally, discoveries like this one can further our understanding of fast radio bursts, an enigmatic and mysterious cosmic phenomenon.

In summary, the recent discovery of unusual radio signals from XTE J1810-197 has opened up new doors for research and has brought to light unexpected and unprecedented behavior in magnetars. With further investigation, we can continue to unlock the mysteries of these powerful cosmic objects.