| Texto completo | |
| Autor(es): |
Madeira, G.
;
Morgado, B. E.
;
Pereira, C. L.
;
Ramon, G.
;
Sfair, R.
;
Braga-Ribas, F.
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ASTROPHYSICAL JOURNAL; v. 994, n. 2, p. 9-pg., 2025-12-01. |
| Resumo | |
A recent stellar occultation revealed that the Centaur (2060) Chiron hosts a broad disk extending beyond similar to 200 km from its center, embedding three ring-like structures (Chi1R, Chi2R, and Chi3R), while a tenuous outer ring (Chi4R) lies beyond the Roche limit. Here, we present a first dynamical assessment of the system's stability through numerical simulations of test particles, accounting for Chiron's triaxial figure. For an equatorial ellipticity of C22 similar to 0.02, as inferred from the most recent shape estimates, our simulations reveal a chaotic inner zone extending to similar to 260 km, where particle lifetimes reach up to a year, while particles beyond similar to 260 km can remain stable for at least a decade. These results suggest that the innermost portion of the disk is ephemeral and can only persist if continuously replenished. For lower ellipticity values (C22 less than or similar to 0.012), however, the entire disk is located within the stable region, regardless of Chiron's mass. Under the physical parameters currently available in the literature, Chi2R is possibly linked to the 1:3 spin-orbit resonance, while Chi1R cannot be linked to the 1:2 resonance, as previously proposed, since this resonance is unstable. Instead, Chi1R and Chi3R may be associated with the 2:5 and 1:5 spin-orbit resonances, respectively. Both the 1:3 and 1:5 resonances are bifurcated, generating chaotic zones that may explain the gap in Chi2R and the longitudinal asymmetry observed in Chi3R. (AU) | |
| Processo FAPESP: | 24/20150-1 - Formação e evolução de estruturas de anéis ao redor de pequenos corpos do sistema solar: aplicação a Centauros. |
| Beneficiário: | Giovana Ramon Luiz Neto |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |