Resonant trans-Neptunian object
Detailed analytical and numerical studies of Neptune's resonances have shown that the objects must have a relatively precise range of energies.
It is now believed that the objects have been collected from wider distances by sweeping resonances during the migration of Neptune.
[4] Well before the discovery of the first TNO, it was suggested that interaction between giant planets and a massive disk of small particles would, via angular-momentum transfer, make Jupiter migrate inwards and make Saturn, Uranus, and especially Neptune migrate outwards.
[5] A few objects have been discovered following orbits with semi-major axes similar to that of Neptune, near the Sun–Neptune Lagrangian points.
[6] Of these 383 confirmed plutinos, 338 have their orbits secured in simulations run by the Deep Ecliptic Survey.
[7] The objects following orbits in this resonance are named plutinos after Pluto, the first such body discovered.
Large, numbered plutinos include: As of February 2020, 47 objects are confirmed to be in a 3:5 orbital resonance with Neptune at 42.2 AU.
[7] As of February 2020[update], 55 4:7-resonant objects have had their orbits secured by the Deep Ecliptic Survey.
Johnston's Archive counts 111 while simulations by the Deep Ecliptic Survey have confirmed 126 as of February 2020.
[6] A dozen of these are secure according to the Deep Ecliptic Survey:[7] As of February 2024, the following higher-order resonances are confirmed for a limited number of objects:[7] Haumea is thought to be in an intermittent 7:12 orbital resonance with Neptune.
[15] One of the concerns is that weak resonances may exist and would be difficult to prove due to the current lack of accuracy in the orbits of these distant objects.
Due to their great distance and slow movement against background stars, it may be decades before many of these distant orbits are determined well enough to confidently confirm whether a resonance is true or merely coincidental.
[citation needed] (See Toward a formal definition) Simulations by Emel'yanenko and Kiseleva in 2007 show that (131696) 2001 XT254 is librating in a 3:7 resonance with Neptune.
The Deep Ecliptic Survey introduced formally defined dynamical classes based on long-term forward integration of orbits under the combined perturbations from all four giant planets.
(see also formal definition of classical KBO) In general, the mean-motion resonance may involve not only orbital periods of the form where p and q are small integers, λ and λN are respectively the mean longitudes of the object and Neptune, but can also involve the longitude of the perihelion and the longitudes of the nodes (see orbital resonance, for elementary examples) An object is resonant if for some small integers (p,q,n,m,r,s), the argument (angle) defined below is librating (i.e. is bounded):[17] where the
[18] All new plutinos discovered during the Deep Ecliptic Survey proved to be of the type similar to Pluto's mean-motion resonance.
Finally, if only one orbit passes the test, the vicinity of the resonance is noted to encourage further observations to improve the data.
[19] The two extreme values of the semi-major axis used in the algorithm are determined to correspond to uncertainties of the data of at most 3 standard deviations.
