The astronomers mentioned in their paper, which is still under review by Nature Astronomy, “We have found an unexpected class of astronomical objects which have not previously been reported, in the Evolutionary Map of the Universe Pilot survey, using the Australian Square Kilometre Array Pathfinder telescope.â€.
All four ORCs were found to only be observable at radio wavelengths and didn’t show up on either the optical, infrared or X-ray wavelengths.