Chariklo asteroid rings show unexpected changes via JWST

Observations from the James Webb Space Telescope (JWST) have revealed that the ring system surrounding the Centaur asteroid Chariklo is changing more rapidly than previously expected. By analyzing a stellar occultation from October 2022, researchers found that Chariklo’s dense inner ring has become significantly more opaque, while its fainter outer ring has become less opaque compared to measurements taken over the last decade.

Because the ring system is too small to be photographed directly, astronomers used the technique of stellar occultation, measuring the drop in light from a distant star as the rings passed in front of it. The JWST’s slow relative passage allowed for a spatial resolution of approximately 750 meters.

Led by the Institute of Astrophysics of Andalusia (IAA-CSIC), the research team noted that these contrasting shifts challenge the assumption that ring systems around small celestial bodies remain stable over short periods. Scientists have not yet determined if these changes are caused by the physical movement and redistribution of ring material, wavelength effects, or a combination of both.