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Astronomers have identified a rare star emitting radio waves and X-rays, exhibiting behavior never seen before, located 15,000 light-years from Earth.
In a groundbreaking find, a star emitting radio waves and X-rays has been discovered in the Milky Way galaxy, approximately 15,000 light-years from Earth in the direction of the constellation Scutum. The star flashes every 44 minutes in both wavelengths, a peculiar trait that has placed it in a unique class of celestial bodies.
This unusual star belongs to a recently identified group known as “long-period radio transients,” characterized by bright bursts of radio waves that recur over minutes to hours, far longer than the millisecond-to-second pulses emitted by conventional pulsars. Pulsars are rapidly spinning neutron stars formed from the collapsed cores of massive stars.
“What these objects are and how they generate their unusual signals remain a mystery,” said Ziteng Wang, lead author of the study published in Nature and an astronomer at Curtin University in Australia.
Multi-Telescope Observations Reveal Unusual Activity
Using data from NASA’s Chandra X-ray Observatory, Australia’s ASKAP telescope, and other global observatories, scientists confirmed that while other known members of this class emit only radio waves, this star is the first known to emit both radio waves and X-rays. This makes it the most exotic example yet of a star emitting radio waves and X-rays.
Co-author Nanda Rea, an astrophysicist from the Institute of Space Sciences in Barcelona, said the emission pattern is unprecedented. Researchers speculate the star might be a magnetar — a neutron star with a massive magnetic field — or possibly a white dwarf orbiting closely with a smaller companion in a binary system. Yet neither explanation fully accounts for the observed phenomena.
White dwarfs are the remnants of stars up to eight times the mass of our sun. After exhausting their hydrogen fuel, they go through a red giant phase and shed their outer layers, leaving behind a dense core about the size of Earth.
The team believes the observed radio waves may stem from interactions between the white dwarf and its hypothesized companion star.
“The radio brightness of the object varies a lot. We saw no radio emission before November 2023, but by February 2024, it became extremely bright,” Wang noted. “Only about 30 objects have ever reached such levels of brightness in radio waves.”
Coincidentally, NASA’s Chandra telescope captured X-ray pulses from the star while observing another target, offering a rare and lucky glimpse during its brightest phase. “We can still detect it in radio, but it’s much fainter now,” Wang added. “It’s thrilling to witness such a new kind of stellar behavior.”
This discovery opens new avenues in understanding extreme stellar phenomena and the rare class of stars emitting radio waves and X-rays.
