Picture this: a flawless, circular mystery drifting through the heart of the Milky Way, leaving top astronomers scratching their heads in disbelief – something utterly unprecedented in our cosmic understanding!
But here's where it gets controversial... In late 2019, stargazers uncovered bizarre formations in the heavens, popping up as flawless circles in data from radio waves. These peculiar anomalies, dubbed Odd Radio Circles or ORCs, were traced back to massive blasts in distant galaxies, far removed from our own Milky Way by billions of light-years. Since that groundbreaking find, only a scant few have been spotted. Yet, stumbling upon one within our very own galaxy has flipped our assumptions upside down.
That said, the phenomenon just detailed by scientists from the University of Western Sydney in Australia, as outlined in their paper for the Publications of the Astronomical Society of Australia, might be equally mind-boggling, but it's not classified as one of those enigmatic 'strange radio circles.' Experts are firm on that point, despite G305.4-2.2 manifesting as an almost impeccable sphere, detectable solely through radio wavelengths. (For beginners, radio waves are a type of electromagnetic radiation with longer wavelengths than visible light, invisible to the naked eye but picked up by specialized telescopes to reveal hidden aspects of the universe, like gas clouds or distant explosions.) They've also dismissed several alternative explanations, such as planetary nebulae – glowing shells created when aging stars shed their outer layers at life's end – or Wolf-Rayet bubbles, expansive regions sculpted by gas expelled from the universe's heftiest stars. And don't forget the Dyson sphere, a colossal artificial construct theorized to be engineered by advanced alien societies to harness a star's energy. This idea was discarded because the object showed no telltale infrared glow from within.
With those options eliminated, astronomers turned their focus to the path of a supernova remnant. To grasp this, let's break it down simply: a supernova happens when a star detonates in a cataclysmic explosion, hurling out a shell of debris that swells into space, observable via telescopes. These leftovers, known as supernova remnants, often appear as irregular shells. They're seldom perfectly round due to the asymmetric nature of the blast or the uneven density of the surrounding interstellar space – the vast, empty stretches between stars filled with gas and dust.
In stark contrast, G305.4-2.2 stands out as nearly flawlessly spherical, earning it the nickname Teleios, derived from the Greek word for 'perfection.' This oddity has researchers puzzled, but they pressed on, leveraging information gathered by the Australian Square Kilometre Array Pathfinder (ASKAP), a powerful radio telescope network.
And this is the part most people miss... The object's faint brightness allowed estimates of its distance from Earth, pegged at roughly 7,175 light-years or possibly 25,114 light-years – a frustrating range that astronomers can't narrow down definitively. Consequently, estimates for Teleios's diameter vary widely, from about 46 to 157 light-years. Since a remnant's size correlates with its age, this anomaly could be a mere 1,000 years young or over 10,000 years old.
After crunching all the numbers, the University of Western Sydney team leans toward the scenario of a Type Ia supernova remnant – the kind triggered when a white dwarf star accumulates too much material from a nearby companion and detonates violently. Still, concrete proof remains elusive, and they're banking on upcoming detailed, high-resolution scans across multiple frequencies to crack the case. Studying these remnants is crucial because they drive galactic evolution, infusing the space between stars with elements and shaping the structure and properties of the interstellar medium. To date, we've cataloged around 300 in the Milky Way, but experts speculate there could be more than 2,000 lurking undetected – imagine how many more secrets our galaxy might hold!
What do you think this enigmatic sphere really is? Could it hint at extraterrestrial activity, or is it just an unusual natural occurrence? And if it's a supernova remnant, why such perfect symmetry – does that challenge our models of stellar explosions? Share your opinions in the comments; I'd love to hear if you agree or disagree!
About the author
Dr. Rosalia Neve
Dr. Rosalia Neve is a sociologist and public policy researcher based in Montreal, Quebec. She earned her Ph.D. in Sociology from McGill University, where her work explored the intersection of social inequality, youth development, and community resilience. As a contributor to EvidenceNetwork.ca, Dr. Neve focuses on translating complex social research into clear, actionable insights that inform equitable policy decisions and strengthen community well-being.
