Uranus trojans

A Uranus trojan is an asteroid that shares an orbit with Uranus and the Sun. Predicted in simulations earlier,[1] two trojans have been discovered in Uranus’s Lagrangian point L₄ (leading Uranus).

(687170) 2011 QF99 was the first body to be classified as such a trojan in 2013, while in 2017 (636872) 2014 YX49 became the second.[2]

Several theories have come to be on how such trojans could orbit Uranus. Gravitational scattering is the most popular, stating that such asteroids (or comets) could have been gravitationally pulled by the other planets, leading them on a perfect trajectory towards Uranus, or somewhere where Uranus’s gravitational pull is neutral.

List of Uranus trojans[3]

Designation	Cloud	Semimajor axis (AU)	Perihelion (AU)	Eccentricity	Inclination (°)	(H)	Diameter (M)
(687170) 2011 QF99	L4	19.167	15.765	0.177	10.796	9.6	60
(636872) 2014 YX49	L4	19.113	13.762	0.279	25.524	8.79	77

References

1. Dvorak, Bazsó & Zhou 2010.
2. de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (21 May 2017). "Asteroid 2014 YX₄₉: a large transient Trojan of Uranus". Monthly Notices of the Royal Astronomical Society. 467 (2): 1561–1568. arXiv:1701.05541. Bibcode:2017MNRAS.467.1561D. doi:10.1093/mnras/stx197.
3. "Small-Body Database Lookup". ssd.jpl.nasa.gov. Retrieved 2024-03-28.

Sources

• Dvorak, R.; Bazsó, á.; Zhou, L.-Y. (2010). "Where are the Uranus Trojans?". Celestial Mechanics and Dynamical Astronomy. 107 (1–2): 51–62. arXiv:0911.2366. Bibcode:2010CeMDA.107...51D. doi:10.1007/s10569-010-9261-y. ISSN 0923-2958.
• Zhou, Lei; Zhou, Li-Yong; Dvorak, Rudolf; Li, Jian (2020). "Systematic survey of the dynamics of Uranus Trojans". Astronomy & Astrophysics. 633: A153. arXiv:1912.10273. Bibcode:2020A&A...633A.153Z. doi:10.1051/0004-6361/201936332. ISSN 0004-6361.