Published September 2021
| Version v1
Journal article
An advanced multipole model for (216) Kleopatra triple system
Creators
- Brož, M.
- Marchis, F.
- Jorda, L.
- Hanuš, J.
- Vernazza, P.
- Ferrais, M.
- Vachier, F.
- Rambaux, N.
- Marsset, M.
- Viikinkoski, M.
- Jehin, E.
- Benseguane, S.
- Podlewska-Gaca, E.
- Carry, B.
- Drouard, A.
- Fauvaud, S.
- Birlan, M.
- Berthier, J.
- Bartczak, P.
- Dumas, C.
- Dudziński, G.
- Ďurech, J.
- Castillo-Rogez, J.
- Cipriani, F.
- Colas, F.
- Fetick, R.
- Fusco, Thierry
- Grice, J.
- Kryszczynska, A.
- Lamy, Philippe
- Marciniak, A.
- Michalowski, T.
- Michel, P.
- Pajuelo, M.
- Santana-Ros, T.
- Tanga, P.
- Vigan, Arthur
- Vokrouhlický, D.
- Witasse, O.
- Yang, B.
Contributors
Others:
- Institute of Astronomy [Prague] ; Charles University [Prague] (CU)
- Search for Extraterrestrial Intelligence Institute (SETI)
- Laboratoire d'Astrophysique de Marseille (LAM) ; Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
- Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE) ; Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris ; Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
- Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS) ; Massachusetts Institute of Technology (MIT)
- Tampere University of Technology [Tampere] (TUT)
- Space Sciences, Technologies and Astrophysics Research Institute (STAR) ; Université de Liège
- SETI Institute
- Ondřejov Observatory of the Prague Astronomical Institute ; Czech Academy of Sciences [Prague] (CAS)
- Observatoire de la Côte d'Azur (OCA) ; Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
- Observatoire du Bois de Bardon
- Astronomical Institute of Romanian Academy ; Romanian Academy
- Thirty Meter Telescope Observatory
- Jet Propulsion Laboratory (JPL) ; NASA-California Institute of Technology (CALTECH)
- European Space Research and Technology Centre (ESTEC) ; Agence Spatiale Européenne = European Space Agency (ESA)
- DOTA, ONERA, Université Paris Saclay [Châtillon] ; ONERA-Université Paris-Saclay
- School of Physical Sciences [Milton Keynes] ; Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes] ; The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU)
- PLANETO - LATMOS ; Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
- Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP)
- Universidad de Alicante
- Institut de Ciencies del Cosmos (ICCUB) ; Universitat de Barcelona (UB)
- European Southern Observatory [Santiago] (ESO) ; European Southern Observatory (ESO)
Description
To interpret adaptive-optics observations of (216) Kleopatra, we need to describe an evolution of multiple moons orbiting an extremely irregular body and include their mutual interactions. Such orbits are generally non-Keplerian and orbital elements are not constants. Consequently, we used a modified N -body integrator, which was significantly extended to include the multipole expansion of the gravitational field up to the order ℓ = 10. Its convergence was verified against the 'brute-force' algorithm. We computed the coefficients C ℓm , S ℓm for Kleopatra's shape, assuming a constant bulk density. For Solar System applications, it was also necessary to implement a variable distance and geometry of observations. Our χ 2 metric then accounts for the absolute astrometry, the relative astrometry (second moon with respect to the first), angular velocities, and silhouettes, constraining the pole orientation. This allowed us to derive the orbital elements of Kleopatra's two moons. Using both archival astrometric data and new VLT/SPHERE observations (ESO LP 199.C-0074), we were able to identify the true periods of the moons, P 1 = (1.822359 ± 0.004156) d, P 2 = (2.745820 ± 0.004820) d. They orbit very close to the 3:2 mean-motion resonance, but their osculating eccentricities are too small compared to other perturbations (multipole, mutual), meaning that regular librations of the critical argument are not present. The resulting mass of Kleopatra, m 1 = (1.49 ± 0.16) × 10 −12 M ⊙ or 2.97 × 10 18 kg, is significantly lower than previously thought. An implication explained in the accompanying paper is that (216) Kleopatra is a critically rotating body.
Abstract
International audienceAdditional details
Identifiers
- URL
- https://hal-insu.archives-ouvertes.fr/insu-03372817
- URN
- urn:oai:HAL:insu-03372817v1