The Rings of Chariklo: A Dance of Dust and Light express
Using the most powerful space telescope, James Webb, astronomers peeked into the cosmic dressing room and saw how the rings of asteroid Chariklo are changing. By observing a passage in front of a star (when the body casts a mini-eclipse on a distant star, a standard method for finding planets around other stars) they discerned: the inner ring grew denser, as if more partners had joined the dance, while the outer almost dissolved into darkness.
Both rings are made of cosmic dust and ice, but they behave differently. The inner one is constantly replenished by ejections from Chariklo's surface — energetic steps that keep the dance alive. The outer, conversely, thins out, yielding to the starlight. This suggests that such ring systems are not an eternal show, but rather a fleeting performance. Chariklo, the centaur hybrid, turns out to be far more changeable than previously thought: its rings live and vanish faster than those of planets.
Original abstract
as written by the authors arXiv:2510.06366
Ring systems have been discovered around several small bodies in the outer Solar System through stellar occultations. While such measurements provide key information about ring geometry and dynamical interactions, little is known about their origins, lifetimes, evolutionary pathways, or compositions. Here we report near-infrared observations with the James Webb Space Telescope (JWST) of a stellar occultation by (10199) Chariklo, a Centaur known to host a double-ring system. Our JWST measurements show that Chariklo's inner dense ring has become significantly more opaque than in previous observations, pointing to ongoing replenishment processes or dynamical restructuring. In contrast, the outer ring exhibits a much weaker near-infrared occultation signature than seen in earlier visible-light detections. This discrepancy may reflect material loss, suggesting that the outer ring could be transient, or may arise from wavelength-dependent opacity. These scenarios, which are not mutually exclusive, point to an unprecedented level of complexity in small-body ring systems, distinct from those observed around any other minor bodies in the Solar System.
From Earth, Chariklo's rings are invisible to any telescope: they reveal themselves only through brief 'winks' of stars as the asteroid passes in front of them.