An Irregular Shape of the Jupiter Trojan (3317) Paris Revealed by Stellar Occultations and Rotational Light Curves

Résumé fourni par la source

Abstract Jupiter Trojans are key remnants of the solar system formation, preserving primordial material and recording the history of planetary migration. We present the first 3D shape model of the Jupiter Trojan (3317) Paris, obtained by combining stellar occultations and rotational light curves. We analyzed 12 occultation events between 2020 and 2022, yielding 27 positive light curves. In addition, we compiled 45 rotational light curves covering ∼8 yr, obtained from observations at the Observatório do Pico dos Dias (OPD-Brazil) and from publicly available databases such as the Asteroid Light Curve Data Exchange Format. Light-curve inversion, combined with occultation constraints, yielded an irregular 3D shape model with an equivalent-volume diameter of 126.2 ± 6.2 km and an equivalent-surface diameter of 131.5 ± 6.5. We refined the rotation period to 7.081013 ± 0.000005 hr, consistent with previous estimates and the spin axis as λ = 100 . ° 5 ± 1 . ° 1 and β = 50 . ° 7 ± 1 . ° 4. Using the surface-equivalent diameter of the shape model, we determined a geometric albedo of p V = 0.045 ± 0.002 for Paris. This study contributes to improving our understanding of the physical properties of Jupiter Trojans, and the methodologies developed in this work can be applied to the study of other small bodies in the solar system.