A mysterious ring of radio light, dubbed Kýklos, has been discovered by astronomers using the MeerKAT radio telescope in South Africa. This discovery challenges our understanding of these enigmatic celestial objects known as ‘odd radio circles’ (ORCs).
ORCs are strange rings of radio light, invisible at other wavelengths, with no obvious source. Previously, all ORCs were found at high galactic latitudes, suggesting they were either very close to us within our galaxy or extragalactic. Some ORCs contain a galaxy at the center, indicating they could be caused by outbursts from these galaxies. However, Kýklos breaks this pattern.
Located just six degrees above the plane of the Milky Way, Kýklos is nestled within our galaxy, appearing close to the galactic center. It’s a perfect circle, spanning 80 arcseconds in the sky, and emits a surprisingly flat radio spectrum, unlike other ORCs.
Astronomers have ruled out several potential explanations for Kýklos. The presence of galaxies within the ring’s boundary, while suggestive of an extragalactic origin, cannot explain its flat spectrum. Supernova remnants, another possibility, usually emit X-rays, which have not been detected from Kýklos.
The most plausible explanation, according to researchers, is a Wolf-Rayet star. These massive stars generate powerful radiation winds that blow their outer layers into space, leaving behind a distinctive signature in the radio spectrum. While a Wolf-Rayet nebula has not been directly observed within Kýklos, the flat spectrum supports this scenario.
However, confirmation requires further observation. The James Webb Space Telescope will be used to gather spectral data on a potential Wolf-Rayet star located within the Kýklos region. This information could finally solve the mystery surrounding this enigmatic ring of radio light and provide valuable insights into the evolution of massive stars in our galaxy.
