The rings of (2060) Chiron: Evidence of an evolving system
Abstract
The centaur (2060) Chiron has long been a candidate for hosting material in orbit, based on occultation and photometric and spectroscopic data. Here, we present a multichord stellar occultation observed on 2023 September 10 UT that reveals new and complex structures surrounding Chiron. High-cadence light curves show multiple secondary events that are best explained (when compared with a multishell interpretation) with a system of three confined rings located at average radii of 273, 325, and 438 km, the outermost of which lies beyond Chiron's Roche limit. The rings appear coplanar, with a mean pole orientation of {\lambda} = 151{\deg} +/- 4{\deg} and \b{eta} = 20{\deg} +/- 6{\deg}. A broader, disklike structure extends from about 200 to 800 km, and a newly detected faint feature is observed at ~1380 km. Chiron thus appears as the fourth small solar system body known for hosting a ring system. Comparisons with previous occultation events that have occurred since 1994 show that these features are not permanent. With these observations, we may witness for the first time the ongoing formation and evolution of a ring system.
Keywords
Cite
@article{arxiv.2510.12388,
title = {The rings of (2060) Chiron: Evidence of an evolving system},
author = {C. L. Pereira and F. Braga-Ribas and B. Sicardy and R. Leiva and M. Assafin and B. E. Morgado and J. L. Ortiz and P. Santos-Sanz and J. I. B. Camargo and G. Margoti and Y. Kilic and G. Benedetti-Rossi and R. Vieira-Martins and T. F. L. L. Pinheiro and R. Sfair and F. L. Rommel and A. R. Gomes-Júnior and R. C. Boufleur and R. Duffard and J. Desmars and D. Souami and N. Morales and F. Arrese and K. Barkaoui and A. Burdanov and C. A. Colazo and C. A. Domingues and H. Dutra and R. C. Gargalhone and C. Jacques and F. Jablonski and L. Liberato and R. Melia and J. C. Oliveira and M. Sardiña and J. Spagnotto and T. Speranza and A. Wilberger and M. A. Zorzan and L. S. Brito and J. P. Cavalcante and T. Q. Costa and M. Emilio and E. Garcia-Migani and M. Gillon and E. Gradovski and E. Jehin and V. Lattari and M. Malacarne and L. A. Mammana and M. Melita and W. Melo and A. J. Ortiz and P. Quitral-Manosalva and G. Ramon and I. Rodrigues and L. Vanzi},
journal= {arXiv preprint arXiv:2510.12388},
year = {2025}
}
Comments
12 pages, 4 figures, 2 tables. Published in The Astrophysical Journal Letters