Science Advances

JWST stellar occultation reveals unexpected changes in Chariklo’s ring system

2026-09-09

Ring systems have been found around several small bodies in the outer Solar System through stellar occultations. While such observations provide constraints on ring geometry and dynamical interactions, little is known about their origins, lifetimes, or compositions. Here, we report near-infrared stellar-occultation observations obtained with the James Webb Space Telescope (JWST) probing the ring system of the Centaur Chariklo. Our measurements show that Chariklo’s dense inner ring has become significantly more opaque than in previous occultations, suggesting ongoing replenishment or dynamical restructuring. In contrast, the outer ring exhibits a much weaker near-infrared occultation signature than previously observed. This discrepancy may reflect material loss, suggesting that the outer ring could be transient or may arise from wavelength-dependent opacity. These observations demonstrate the power of JWST occultations to probe the evolving structure of rings around small bodies and provide compelling evidence for unexpected changes in Chariklo’s ring system.

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DOI https://doi.org/10.1126/sciadv.aeh4794