| May 28, 2025 |
Cosmic mystery deepens as astronomers find object flashing in both radio waves and X-rays
Astronomers have made a startling discovery about a new type of cosmic phenomenon.
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(Nanowerk News) Astronomers from the International Centre for Radio Astronomy Research (ICRAR), in collaboration with international teams, have made a startling discovery about a new type of cosmic phenomenon (Nature, "Detection of X-ray Emission from a Bright Long-Period Radio Transient").
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The object, known as ASKAP J1832-0911, emits pulses of radio waves and X-rays for two minutes every 44 minutes. ASKAP J1832-0911 is located in our Milky Way galaxy about 15,000 light-years from Earth.
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This is the first time objects like these, called long-period transients (LPTs), have been detected in X-rays. Astronomers hope it may provide insights into the sources of similar mysterious signals observed across the sky.
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| Radio and X-ray lightcurves showing how ASKAP J1832-0911 pulses at both bands. (Image: Ziteng Wang, ICRAR)
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The team discovered ASKAP J1832-0911 by using the ASKAP radio telescope on Wajarri Country in Australia, owned and operated by Australia’s national science agency, CSIRO. They correlated the radio signals with X-ray pulses detected by NASA’s Chandra X-ray Observatory, which was coincidentally observing the same part of the sky.
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“Discovering that ASKAP J1832-0911 was emitting X-rays felt like finding a needle in a haystack,” said lead author Dr Ziteng (Andy) Wang from the Curtin University node of ICRAR.
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“The ASKAP radio telescope has a wide field view of the night sky, while Chandra observes only a fraction of it. So, it was fortunate that Chandra observed the same area of the night sky at the same time.”
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LPTs, which emit radio pulses that occur minutes or hours apart, are a relatively recent discovery. Since their first detection by ICRAR researchers in 2022, ten LPTs have been discovered by astronomers across the world.
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Currently, there is no clear explanation for what causes these signals, or why they ‘switch on’ and ‘switch off’ at such long, regular and unusual intervals.
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“This object is unlike anything we have seen before,” Dr Wang said.
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“ASKAP J1831-0911 could be a magnetar (the core of a dead star with powerful magnetic fields), or it could be a pair of stars in a binary system where one of the two is a highly magnetised white dwarf (a low-mass star at the end of its evolution).”
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However, even those theories do not fully explain what we are observing. This discovery could indicate a new type of physics or new models of stellar evolution.”
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Detecting these objects using both X-rays and radio waves may help astronomers find more examples and learn more about them.
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According to second author Professor Nanda Rea from the Institute of Space Science (ICE-CSIC) and Catalan Institute for Space studies (IEEC) in Spain, “Finding one such object hints at the existence of many more. The discovery of its transient X-ray emission opens fresh insights into their mysterious nature,”
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“What was also truly remarkable is that this study showcases an incredible teamwork effort, with contributions from researchers across the globe with different and complementary expertise,” she said.
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The discovery also helps narrow down what the objects might be. Since X-rays are much higher energy than radio waves, any theory must account for both types of emission – a valuable clue, given their nature remains a cosmic mystery.
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