Four mysterious circular objects made of radio waves spotted in deep space

Four mysterious circular objects made of radio waves have been found by astronomers in deep space. The mysterious objects were detected by kectes Ray Norris, Professor of Applied Data Science in Astrophysics for Western Sydney, with his colleagues by using the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. 

The astronomers detected these circular objects while they were mapping the night sky as part of Evolutionary Map of the Universe (EMU) project. According to astronomers, these mysterious objects are brighter along the edges and that's why they named them odd radio circles, or ORCs.

Norris and his colleagues have submitted the details of these mysterious objects in a new paper posted to arXiv and submitted to Nature Astronomy.

"Circular features are well-known in radio astronomical images, and usually represent a spherical object such as a supernova remnant, a planetary nebula, a circumstellar shell, or a face-on disc such as a protoplanetary disc or a star-forming galaxy," the astronomers write in their paper.

"They may also arise from imaging artefacts around bright sources caused by calibration errors or inadequate deconvolution. Here we report the discovery of a class of circular feature in radio images that do not seem to correspond to any of these known types of object or artefact, but rather appear to be a new class of astronomical object," they added.

The astronomers that all four ORCs are only visible in radio wavelengths and they are completely invisible in X-ray, optical, or infrared wavelengths. It is believed that these mysterious objects could be linked to galactic activity, but the astronomers also found out that only two out of four ORCs have an optical galaxy near the centre of the radio emission.