At the center of the galaxy there is a mysterious radio signal

As our sky-scanning tools become more sophisticated and sensitive, we will find more and more things we've never seen before. This is the case of a newly discovered source of radio signals, located not far from the center of the galaxy. It is called ASKAP J173608.2-321635 and astronomers have not been able to figure out which type of cosmic object best suits its strange properties.

“We presented the discovery and characterization of ASKAP J173608.2 -321635: a highly polarized variable radio source located near the Galactic Center and without a clear multi-wavelength counterpart, ”explains a team of astronomers led by Ziteng Wang of the University of Sydney in Australia. "ASKAP J173608.2-321635 may represent part of a new class of objects discovered through radio imaging investigations."

ASKAP J173608.2-32163 was discovered using the Australian Square Kilometer Array Pathfinder (ASKAP) , one of the most sensitive radio telescopes ever built. Designed to peer deep into the radio Universe, it has already proved adept at finding things we've never seen before, such as Odd Radio Circles (we don't know what they are yet), unknown galaxies and mysterious fast radio bursts.

ASKAP J173608.2-32163 might turn out to be a known type of cosmic object, but if it does, it could end up lengthening the definition of whatever object it is. “We have never seen anything like it,” says Wang.

Understanding what the source of this radio signal could be is really difficult: there are in fact different types of stars known to vary in radio wavelengths, but the lack of detection in X-ray and near infrared wavelengths makes all known hypotheses very unlikely.

However, the object shares some properties with a type of mysterious signal found near the galactic center. These are known as Galactic Center Radio Transients (GCRT), three of which were identified in the 2000s, and others are awaiting confirmation. These sources are also yet to be explained, but they have several characteristics in common with ASKAP J173608.2-32163. If ASKAP J173608.2-32163 is a GCRT, detecting ASKAP could help us find more such sources and understand which ones they are.