Astronomers Discover Most Powerful Dual-Ring Odd Radio Circle in the Cosmos

Astronomers, in collaboration with citizen scientists, have discovered a remarkable dual-ring odd radio circle (ORC)—the strongest and most distant ever detected. Named J131346.9+500320, the structure consists of two intersecting rings of bright radio emission in a faint halo measuring approximately 2.6 million light-years across, with each ring spanning about 978,000 light-years. The light we observe from this cosmic marvel has traveled 7.7 billion years to reach Earth.

The discovery, led by Ananda Hota of the University of Mumbai and founder of the RAD@home citizen science project, suggests that the dual-ring formation may result from powerful winds or giant shocks from a supermassive black hole at the galaxy’s center. Hota emphasizes the synergy between professional astronomers and citizen scientists in uncovering these rare cosmic phenomena.

What Are Odd Radio Circles?

ORCs are peculiar, roughly circular sources of radio emission detected far in intergalactic space. While their exact origin remains uncertain, mounting evidence points to supermassive black holes as the culprits. These black holes can produce enormous jets of plasma, extreme winds, or shockwaves during galactic mergers, all of which can shape the surrounding cosmic environment.

Only two of the dozen known ORCs feature two rings, making J131346.9+500320 exceptionally rare. Researchers propose that we may be observing twin outflows from one object, similar to the twin jets seen in active black holes, but manifesting in a different, circular form.

Formation Mechanism Insights

The team suggests that galactic superwinds or shocks could compress dormant radio lobes, reaccelerating their particles and producing visible rings or shells. In the case of J131346.9+500320, a bipolar superwind interacting with fading radio lobes could have generated the twin-ring structure. The emission detected is primarily old, fading synchrotron radiation, making the ORC a fossil relic of ancient black hole activity, rejuvenated by later energetic events.

The researchers also highlight two other related objects: RAD J122622.6+640622 and RAD J142004.0+621715, both radio galaxies with large ORCs at the ends of bent jets. These discoveries reinforce the idea that ORCs are not isolated curiosities but part of a broader class of exotic plasma structures shaped by black hole jets, winds, and galactic environments, according to astrophysicist Pratik Dabhade.

This finding opens a new window into the complex interplay between supermassive black holes and their host galaxies, providing vital clues about how cosmic structures evolve over billions of years.