Asteroid 2017 FZ2 et al.: signs of recent mass-shedding from YORP?

Abstract

The first direct detection of the asteroidal YORP effect, a phenomenon that changes the spin states of small bodies due to thermal reemission of sunlight from their surfaces, was obtained for (54509) YORP 2000 PH5. Such an alteration can slowly increase the rotation rate of asteroids, driving them to reach their fission limit and causing their disruption. This process can produce binaries and unbound asteroid pairs. Secondary fission opens the door to the eventual formation of transient but genetically-related groupings. Here, we show that the small near-Earth asteroid (NEA) 2017 FZ2 was a co-orbital of our planet of the quasi-satellite type prior to their close encounter on 2017 March 23. Because of this flyby with the Earth, 2017 FZ2 has become a non-resonant NEA. Our N-body simulations indicate that this object may have experienced quasi-satellite engagements with our planet in the past and it may return as a co-orbital in the future. We identify a number of NEAs that follow similar paths, the largest named being YORP, which is also an Earth's co-orbital. An apparent excess of NEAs moving in these peculiar orbits is studied within the framework of two orbit population models. A possibility that emerges from this analysis is that such an excess, if real, could be the result of mass shedding from YORP itself or a putative larger object that produced YORP. Future spectroscopic observations of 2017 FZ2 during its next visit in 2018 (and of related objects when feasible) may be able to confirm or reject this interpretation.

20 pages, 23 figures, 2 tables. Accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journal

References in corpus (12)

• Dynamics of rotationally fissioned asteroids: Source of observed small asteroid systems
• Formation of asteroid pairs by rotational fission
• On the Ages of Resonant, Eroded and Fossil Asteroid Families
• Quasi-satellite orbits in the general context of dynamics in the 1:1 mean motion resonance. Perturbative treatment
• Properties and evolution of NEO families created by tidal disruption at Earth
• Searching for the first Near-Earth Object family
• Meteoroid impacts onto asteroids: a competitor for Yarkovsky and YORP
• Asteroid 2014 OL339: yet another Earth quasi-satellite
• Surface Properties of Asteroids from Mid-Infrared Observations and Thermophysical Modeling
• Asteroid rotation excitation by subcatastrophic impacts
• On the rotation rates and axis ratios of the smallest known near-Earth asteroids---the archetypes of the Asteroid Redirect Mission targets
• Recent multi-kiloton impact events: are they truly random?

Cited by in corpus (7)

• On the orbital evolution of meteoroid 2020 CD3, a temporarily captured orbiter of the Earth-Moon system
• Mini-moons from horseshoes: A physical characterization of 2022 NX1 with OSIRIS at the 10.4 m Gran Telescopio Canarias
• Using Mars co-orbitals to estimate the importance of rotation-induced YORP break-up events in Earth co-orbital space
• Error dependencies in the space-based CNEOS fireball database
• Activity of the Jupiter co-orbital comet P/2019~LD${}_2$ (ATLAS) observed with OSIRIS at the 10.4 m GTC
• Disruption of exo-asteroids around white dwarfs and the release of dust particles in debris rings in co-orbital motion
• When the horseshoe fits: Characterizing 2023 FY3 with the 10.4 m Gran Telescopio Canarias and the Two-meter Twin Telescope