Shepherding Miorita and its flock: A group of near-Earth asteroids driven by apsidal and von Zeipel-Lidov-Kozai secular resonances. A source of low-perihelion asteroids

Abstract

Context. Secular resonances can control the dynamical evolution of near-Earth asteroids (NEAs) and, in some cases, lead to increased orbital stability. Asteroid 622577 Miorita (2014 LU14) was the first NEA found by the Isaac Newton Telescope (INT) and exhibits unusual dynamical traits although it approaches Venus, Earth, and Mars at relatively close range. Aims. Here, we investigate the orbital context of Miorita and search for possible dynamical analogs within the NEA population. Methods. We studied the orbital evolution of Miorita using direct N-body calculations. We used the NEOMOD 3 orbital distribution model to verify our conclusions. Observational data were obtained with INT's Wide Field Camera. Results. Miorita is subjected to a von Zeipel-Lidov-Kozai secular resonance, but it is also in a near apsidal resonance, both controlled by Jupiter. We identified a group of dynamical analogs of Miorita that includes 387668 (2002 SZ), 2004 US1 , 299582 (2006 GQ2), and 2018 AC4. Miorita-like orbits can evolve into metastable, low-perihelion trajectories driven by apsidal and von Zeipel-Lidov-Kozai secular resonances like those of 504181 (2006 TC) and 482798 (2013 QK48). Objects in such paths may end up drawn into the Sun. Conclusions. Concurrent secular resonances tend to stabilize the orbits of these asteroids as they are protected against collision with Earth and other inner planets by the resonances. This group signals the existence of an active dynamical pathway capable of inserting NEAs in comet-like orbits. NEOMOD 3 gives a low probability for the existence of NEAs like Miorita, 504181 or 482798.