Stability mapping of the new Uranian moon S/2025 U1 with updated masses for Cordelia, Ophelia, and Cressida
- 1Federal Institute of Education, Science and Technology of Alagoas (IFAL), Palmeira dos Índios
- 2Group of Orbital & Rotational Research in Irregular Objects & Observational astroNomy (ORION)
- 3Group of Orbital Dynamics & Planetology, São Paulo State University (Unesp), School of Engineering and Sciences, Guaratinguetá, São Paulo
Abstract
We investigate the dynamics of Uranus’s inner satellite system considering three recent updates: the inclusion of the new moon S/2025 U1; revised mass estimates for Cordelia, Ophelia, and Cressida; and updated zonal harmonic coefficients (J2, J4, and J6). Using numerical integrations, mean-motion resonance analysis, and frequency map analysis (FMA), we explored their impact on orbital stability. For the first time, we analyzed the dynamics of the newly discovered moon S/2025 U1 and find that it follows a stable orbit, exhibiting smooth variations in its orbital elements over 250 000 years. Depending on the adopted radius, the gravitational influence of S/2025 U1 on the surrounding region is more compatible with a body of approximately 5–7 km in radius, producing diffusion maps associated with a regular orbital evolution. Furthermore, the case R = 7 km shows a reduction in the diffusion of neighboring satellites, suggesting a possible local stabilizing effect on the system’s orbital evolution. We also identified inner and outer regions of low diffusion around its orbit, suggesting that the dynamical environment is compatible with the survival of coorbital particles or additional small satellites. In contrast, very high radius values, particularly R = 20 km, tend to increase diffusion among neighboring satellites, making this scenario less compatible with a dynamically stable orbital configuration. We further explored the survival of hypothetical satellites near S/2025 U1. Our results show that bodies with masses up to 3× that of S/2025 U1 can remain stable in both the interior (between S/2025 U1 and Ophelia) and the exterior (between S/2025 U1 and Bianca) of its orbit. Finally, we find that the group formed by Cressida, Desdemona, Juliet, and Portia is the most sensitive to the updated parameters, showing noticeable changes in orbital stability and in the evolution of maximum eccentricity. While most mean-motion resonances among the satellites exhibit a circulating behavior, the 44:43 resonance between Belinda and Perdita acts as a confinement mechanism for the Belinda-Cupid-Perdita system, with a libration amplitude smaller than previously reported.
Versions
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BibTeX
@article{xavier2026stability,
title = {{Stability mapping of the new Uranian moon S/2025 U1 with updated masses for Cordelia, Ophelia, and Cressida}},
author = {Xavier J. and Amarante A. and Giuliatti Winter S. and Ferreira A.},
journal = {Astronomy \& Astrophysics},
year = {2026},
month = oct,
doi = {10.1051/0004-6361/202558328},
url = {https://doi.org/10.1051/0004-6361/202558328},
note = {CC BY},
}
RIS
TY - JOUR
TI - Stability mapping of the new Uranian moon S/2025 U1 with updated masses for Cordelia, Ophelia, and Cressida
AU - Xavier J.
AU - Amarante A.
AU - Giuliatti Winter S.
AU - Ferreira A.
PY - 2026
DA - 2026/10/24
JO - Astronomy & Astrophysics
DO - 10.1051/0004-6361/202558328
UR - https://doi.org/10.1051/0004-6361/202558328
AB - We investigate the dynamics of Uranus’s inner satellite system considering three recent updates: the inclusion of the new moon S/2025 U1; revised mass estimates for Cordelia, Ophelia, and Cressida; and updated zonal harmonic coefficients (J2, J4, and J6). Using numerical integrations, mean-motion resonance analysis, and frequency map analysis (FMA), we explored their impact on orbital stability. For the first time, we analyzed the dynamics of the newly discovered moon S/2025 U1 and find that it follows a stable orbit, exhibiting smooth variations in its orbital elements over 250 000 years. Depending on the adopted radius, the gravitational influence of S/2025 U1 on the surrounding region is more compatible with a body of approximately 5–7 km in radius, producing diffusion maps associated with a regular orbital evolution. Furthermore, the case R = 7 km shows a reduction in the diffusion of neighboring satellites, suggesting a possible local stabilizing effect on the system’s orbital evolution. We also identified inner and outer regions of low diffusion around its orbit, suggesting that the dynamical environment is compatible with the survival of coorbital particles or additional small satellites. In contrast, very high radius values, particularly R = 20 km, tend to increase diffusion among neighboring satellites, making this scenario less compatible with a dynamically stable orbital configuration. We further explored the survival of hypothetical satellites near S/2025 U1. Our results show that bodies with masses up to 3× that of S/2025 U1 can remain stable in both the interior (between S/2025 U1 and Ophelia) and the exterior (between S/2025 U1 and Bianca) of its orbit. Finally, we find that the group formed by Cressida, Desdemona, Juliet, and Portia is the most sensitive to the updated parameters, showing noticeable changes in orbital stability and in the evolution of maximum eccentricity. While most mean-motion resonances among the satellites exhibit a circulating behavior, the 44:43 resonance between Belinda and Perdita acts as a confinement mechanism for the Belinda-Cupid-Perdita system, with a libration amplitude smaller than previously reported.
SN - 0004-6361
SN - 1432-0746
ER -