Askap J1832-0911 – Likely a magnetar or a highly magnetized white dwarf star – emits radio signals and X-ray pulses for 2 minutes every 44 minutes. Paper published in Nature.
A combination of radio, X-ray, and infrared radiation in the field of ASKAP J1832-0911. Image credit: Wang et al., doi: 10.1038/S41586-025-09077-W.
Askap J1832-0911 is situated roughly 15,000 light-years away from Earth in Scutum.
This star was identified by astronomers utilizing the Australian ASKAP Radio telescope.
It belongs to a category known as long-term radio transients, first detected in 2022, characterized by variations in radio wave intensity over several minutes.
This duration is thousands of times greater than the regular fluctuations observed in pulsars. It’s a neutron star that spins rapidly, emitting signals multiple times per second.
“Askap J1832-0911 follows a 44-minute cycle of radio wave intensity, placing it in the realm of long-term radio transients,” stated Dr. Ziteng Wang, an astronomer at Curtin University’s node at the International Centre for Radio Astronomical Research (ICRAR).
Using NASA’s Chandra X-Ray Observatory, researchers noted that ASKAP J1832 also exhibited regular variations in X-ray emissions every 44 minutes.
This marks the first discovery of an X-ray signal in long-term radio transients.
“Astronomers have observed countless celestial bodies through various telescopes and have never encountered anything behaving like this,” Dr. Wang remarked.
“It’s exhilarating to witness such new stellar phenomena.”
Through Chandra and the SKA Pathfinder, scientists found that Askap J1832-0911 experienced a significant reduction in both X-ray and radio wave signals over a six-month period.
Besides the long-term changes, the combination of 44-minute cycles in X-rays and radio waves differs from observations made in the Milky Way galaxy.
The authors are currently competing to determine whether Askap J1832-0911 truly represents long-term radio transients and if its unusual behavior can shed light on the origins of such objects.
Dr. Nanda Lea, an astronomer at the Institute of Space Sciences in Barcelona, Spain, commented:
“No exact match has been found so far, but some models fit better than others.”
It’s improbable that ASKAP J1832-0911 is simply a pulsar or neutron star drawn from a companion star, as its properties do not align with the typical signal strengths of these celestial objects.
Some characteristics might be attributed to neutron stars with exceptionally strong magnetic fields, known as magnetars, which are over 500,000 years old.
However, other aspects, such as its bright and variable radio emissions, make it challenging to categorize this as an aged magnetar.
In the sky, ASKAP J1832-0911 appears to be situated among debris from a supernova, which commonly contains neutron stars formed during such events.
Nevertheless, the team concluded that this proximity is likely coincidental and that the two entities are not associated with one another, suggesting that neither may host neutron stars.
They deduced that while isolated white dwarfs don’t account for the data, white dwarfs with companion stars might.
But such a scenario would necessitate the strongest known magnetic fields in white dwarfs within our galaxy.
“We continue to seek clues about this object and look for similar entities,” said Dr. Tong Bao, an astronomer at the Osservatorio Astronomico in Italy’s National Institute of Astronomy (INAF).
“Discovering mysteries like this is not frustrating; rather, it’s what makes science thrilling!”
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Z. Wang et al. Detection of X-ray radiation from bright long-term radio transients. Nature Published online on May 28, 2025. doi:10.1038/s41586-025-09077-W
Source: www.sci.news
