Signals

Astronomers have discovered a strange new object that behaves unlike any observed before. The hope is that the source will provide some much-needed insight into the origin of mysterious cosmic signals that have puzzled experts for the last several years.

A team of researchers led by astronomers from the International Centre for Radio Astronomy Research (ICRAR) in Australia found the object—known as ASKAP J1832-0911—using the ASKAP radio telescope, which picked up pulses of radio waves emanating from it.

This suggests that it belongs to a mysterious, recently discovered class of objects called long-period transients (LPTs), which emit radio pulses over unusually long and regular intervals—typically minutes or hours apart. Since LPT signals were first detected by ICRAR astronomers in 2022, only 10 of these objects have been documented, according to a statement from the organization.

Astronomers are still trying to figure out exactly what LPTs are and why they exhibit such odd behavior. In March, there appeared to be a new break in the case when a study linked LPT pulses to a binary star system composed of a white dwarf and a red dwarf, but J1832-0911 has turned out to be especially peculiar. While the ASKAP radio telescope was observing it, NASA’s Chandra X-ray Observatory just so happened to be looking at the same piece of sky. This revealed that the object, located in the Milky Way some 15,000 light-years from Earth, was also sending out pulses of X-rays.

Detecting X-ray emissions from ASKAP J1832-0911 “felt like finding a needle in a haystack,” lead author Ziteng (Andy) Wang, an astronomer at the Curtin University arm of ICRAR, said in the statement. “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.”

This is the first time that X-ray emissions have been observed from an LPT. J1832-0911 emits radio waves and X-rays simultaneously for a period of two minutes over intervals of 44 minutes, exhibiting properties that are “unique amongst known galactic objects and require a new explanation,” the authors state in their paper, published today in the journal Nature.

Uncovering the true nature of J1832-0911 will require further research, but Wang and his colleagues have some initial ideas about what it might be.

“ASKAP [J1832-0911] could be a magnetar (the core of a dead star with powerful magnetic fields),” he said. Simultaneous pulses of radio waves and X-rays have been observed from magnetars before.

Alternatively, “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),” Wang added. In this scenario—which has also been previously documented—the interaction between a rapidly spinning, magnetized white dwarf and its companion causes the system to emit pulses that span the electromagnetic spectrum—from X-rays to radio waves.

But according to Wang and his colleagues, neither of these possibilities can fully explain what they observed from J1832-0911. Thus, this discovery could indicate that some new physics is taking place, or that astronomers need to tweak existing models of stellar evolution.

Now, the search for more of these bizarre objects is on. “Finding one such object hints at the existence of many more,” co-author Nanda Rea, an astrophysicist at the Institute of Space Science (ICE-CSIC) and the Institute of Space Studies of Catalonia (IEEC) in Spain, said in the statement. The discovery of J1832-0911’s transient X-ray emissions “opens up fresh insights” into the mysterious nature of LPTs, she said.

Source link