An arXiv preprint of a JWST stellar occultation of Chariklo on 18 October 2022 reports inner-ring normal opacity of 0.431 plus or minus 0.012 versus a pre-JWST average of 0.303 plus or minus 0.028. Ars Technica Science on 19 September said Chariklo is about 250 km across, has two rings, and that those rings are changing.
The arXiv preprint:2510.06366, last revised 17 December 2025, reports a JWST stellar occultation of Chariklo on 18 October 2022, with the chord about 7.4 km from the body's centre, observed simultaneously at 1.5 and 3.2 micrometres. Ars Technica Science on 19 September 2026 said Chariklo is only about 250 km across but has two rings.[1], [2]
For the inner ring the arXiv authors give a pre-JWST average normal opacity of 0.303 plus or minus 0.028 versus 0.431 plus or minus 0.012 from JWST alone, a difference they quote as z=4.2. The rings C1R and C2R remain near 390 and 405 km from the centre. Ars Technica said those rings are changing. The Ars feed does not add JWST figures.[1], [2]
The arXiv preprint writes that the outer ring is unexpectedly weak in the JWST chords and that a transient outer ring or wavelength-dependent opacity, or both, remain open. The study is still a preprint. Ars Technica on 19 September still described two rings on the small body. Neither card is a Science Advances version.[1], [2]
