They can be everything from the leftovers of a supernova, a planetary nebular, or looking at something such a proto-planetary disc or star-forming galaxy from a certain angle.
They can also be a sign of a bug and may come about when there are bright sources from incorrectly-calibrated telescopes.
However, the newly discovered circles do not appear to be explained by any of those more traditional objects.
Instead, the researchers note, they “appear to be a new class of astronomical object”.
Source:’ – Express.co.uk
