This story is one that screams, “Take me out of context!”

So I will.

According to Professor Ray Norris: No doubt the SKA telescopes, once built, will find many more ORCs.

Backing up and adding some context in, researchers using the MeerKAT and ASKAP radio telescopes have discovered odd radio circles surrounding the occasional galaxy, and since “odd radio circles” makes the acronym ORCs… well, that’s kind of an awesome acronym and these do look a bit like a child’s drawing of an ORC, so these weird structures are now called ORCs.

Beyond telling you they have a cool name, I can’t tell you much about them. They were first spotted in 2020 by the just-starting-to-be-commissioned ASKAP radio array in Australia. This is one of those fabulous cases of a new telescope getting turned on and we see something utterly unexpected. According to Norris: We know ORCs are rings of faint radio emissions surrounding a galaxy with a highly active black hole at its center, but we don’t yet know what causes them, or why they are so rare.

In a new Monthly Notices of the Royal Astronomical Society paper, researchers describe the most detailed observations of an ORC that have so far been captured. Appearing like a set of interlocking rings – rings that could fit sixteen Milky Ways inside of them – this odd structure is really like nothing previously seen.

Leading theories point to huge explosions, perhaps associated with merging supermassive black holes, super weird jets of energetic particles, or the shockwaves of a burst of star formation hitting surrounding material. These theories, however, are based on trying to fit known possibilities to something utterly new, and it’s reasonable to believe something not-yet-imagined is actually causing these structures. As study co-author Jordan Collier puts it: People often want to explain their observations and show that it aligns with our best knowledge. To me, it’s much more exciting to discover something new, that defies our current understanding.

Folks, there are ORCs out there, surrounding galaxies, just waiting to be understood. Isn’t the universe a weird and wonderful place?

More Information

CSIRO press release

“MeerKAT uncovers the physics of an Odd Radio Circle,” Ray P. Norris et al., to be published in Monthly Notices of the Royal Astronomical Society (preprint on arxiv.org)