Astronomers discover new type of object – named ORCs
These new objects are only visible in radio wavelengths and are ring (circular) shaped, hence the acronym ORC (Odd Radio Circles). The 4 discovered are all off the galactic plane so are presumed not in the Milky Way. It is not known how far away they are. They span about 1 arcminute (one twentieth of the moon’s apparent width) and two have galaxies visible within the ring. No convincing expalanations yet – the leading contender may be shockwaves from some event. More are expected to be discovered as this particular radio survey continues (EMU).
Update 4th Dec 2020: A few more ORCs have been noted. Intriguingly, scientists have no idea how far away they are – they could be in our galaxy a few light-years in diameter or they could be far away, millions of light-years across. There is nothing corresponding when viewed with optical telescopes. Several possible explanations have been ruled out – supernova remnants, galaxies experiencing intense star formation, lobes from supermassive black holes and Einstein rings. Russian scientists have even suggested wormhole throats! Based on the analysis done so far, researchers expect to find around 1000 ORCs once the data is fully processed.
