Skip to main content

Astronomers spot a vast, mysterious circle in space

Astronomers have spotted an enormous and mysterious object more than a million light-years across, called an odd radio circle (ORC). ORCs were first identified in 2019, and now researchers have released the highest resolution yet of the strange phenomenon.

The image was captured by the South African Radio Astronomy Observatory’s MeerKAT radio telescope, and astronomers are debating what the source of the huge circles could be. The objects have been detected using radio telescopes, but they seem to be invisible to optical, infrared, and X-ray telescopes.

An odd radio circles (ORC) captured by the MeerKAT radio telescope in South Africa.
An odd radio circles (ORC) captured by the MeerKAT radio telescope in South Africa. J. English (U. Manitoba)/EMU/MeerKAT/DES(CTIO)

The three leading theories for what the cause of the objects, according to the South African Radio Astronomy Observatory, are as follows:  “They could be the remnant of a huge explosion at the center of their host galaxy, like the merger of two supermassive black holes; They could be powerful jets of energetic particles spewing out of the galaxy’s center; or They might be the result of a starburst ‘termination shock’ from the production of stars in the galaxy.”

The objects are almost incomprehensibly vast, and most seem to contain a galaxy at their center, which supports the idea that they could be formed by galactic processes. However, the fact they are only visible in the X-ray wavelength is very strange.

“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,” said one of the authors, Ray Norris, in a statement.

The many open questions about these objects provide fertile ground for further research. The researchers are planning to look at the circles using sensitive radio telescopes like the upcoming Square Kilometre Array (SKA), an array of thousands of antennas spread across Australia and South Africa.

“People often want to explain their observations and show that it aligns with our best knowledge,” said another author, Jordan Collier of the Inter-University Institute for Data Intensive Astronomy. “To me, it’s much more exciting to discover something new, that defies our current understanding.”

The research is available as a pre-print and will be published in the Monthly Notices of the Royal Astronomical Society.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
SpaceX reaches agreement with astronomers to limit Starlink interference
Image showing the disruption of astronomical observations caused by a previous Starlink launch

This week, National Science Foundation announced it has reached an agreement with SpaceX to limit the effects of Starlink satellites on astronomy.

Astronomers have been raising concerns about the effects that Starlink satellites could have on scientific study for several years now, as part of a wider consideration of the cultural and environmental importance of dark and quiet skies. The International Astronomical Union has even set up a special center for addressing the issue of satellite megaconstellations like Starlink on both optical and radio astronomy.

Read more
ISS astronaut spots SpaceX’s Starbase facility from space
SpaceX's Starbase facility as seen from the ISS.

An astronaut gazing out from the International Space Station (ISS) managed to spot SpaceX's Starbase spaceflight facility in Boca Chica, Texas, some 250 miles below.

Japanese astronaut Koichi Wakata photographed the sight from the ISS as the orbital outpost passed over the Lone Star State earlier this week. Posting the image on Twitter, Wakata asked his followers if they could spot SpaceX’s facility far below.

Read more
How astronomers worked together to spot an asteroid before it hit Earth
This time-lapse photograph was taken by astronomer Robert Weryk from near his home in London, Ontario, Canada, after NASA’s Scout system forewarned him about the entry of 2022 WJ1 on Nov. 19, 2022. The resulting fireball streaked directly overhead and continued east until it broke up.

This month, a small asteroid hurtled through space toward the Earth and entered the sky above Toronto. Even though it was only around a meter across and burnt up harmlessly in the atmosphere, this asteroid was notable because it was one of the first few asteroids to strike Earth that we knew was coming.

The asteroid, named 2022 WJ1, was first discovered by a project called the Catalina Sky Survey which uses a telescope at the Catalina Station near Tucson, Arizona. It was seen around four hours before it was due to strike Earth, making it just the sixth asteroid to date identified before impacting Earth. The detection was passed to a group called the Minor Planet Center which brings together international data on near-Earth objects and coordinates follow-up observations with astronomers around the world.

Read more