The Second Earth Trojan 2020 XL${}_5$

Abstract

The Earth Trojans are co-orbitals librating around the Lagrange points $L_4$ or $L_5$ of the Sun-Earth system. Although many numerical studies suggest that they can maintain their dynamical status and be stable on timescales up to a few tens of thousands of years or even longer, they remain an elusive population. Thus far only one transient member (2010 TK${}_7$) has been discovered serendipitously. Here, we present a dynamical study of asteroid 2020 XL${}_5$. With our meticulous followup astrometric observations of the object, we confirmed that it is a new Earth Trojan. However, its eccentric orbit brings it close encounters with Venus on a frequent basis. Based on our N-body integration, we found that the asteroid was captured into the current Earth Trojan status in the 15th century, and then it has a likelihood of 99.5% to leave the $L_4$ region within the next $\sim$10 kyr. Therefore, it is most likely that 2020 XL${}_5$ is dynamically unstable over this timescale.

Accepted to ApJL; 5 figures, 3 tables

References in corpus (5)

• Star catalog position and proper motion corrections in asteroid astrometry
• Non-Gravitational Acceleration of the Active Asteroids
• A Search for L4 Earth Trojan Asteroids Using a Novel Track-Before-Detect Multi-Epoch Pipeline
• Long-term dynamical survival of deep Earth coorbitals
• Search for L5 Earth Trojans with DECam

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• Mission Analysis for the First-Ever Saturn Trojan 2019 UO${}_{14}$
• The steady-state population of Earth's co-orbitals of lunar provenance