0587338 - ASÚ 2025 RIV US eng J - Journal Article
Zhou, W.-H. - Vokrouhlický, D. - Kanamaru, M. - Agrusa, H. - Pravec, Petr - Delbo, M. - Michel, P.
The Yarkovsky effect on the long-term evolution of binary asteroids.
Astrophysical Journal Letters. Roč. 968, č. 1 (2024), č. článku L3. ISSN 2041-8205. E-ISSN 2041-8213
R&D Projects: GA ČR(CZ) GA23-04946S
Institutional support: RVO:67985815
Keywords : 66391 1999 kw4 * detection opportunities * tidal evolution * mutual events * thermal force * spin-state * yorp
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 7.9, year: 2022
Method of publishing: Open access

We explore the Yarkovsky effect on small binary asteroids. While significant attention has been given to the binary YORP effect, the Yarkovsky effect is often overlooked. We develop an analytical model for the binary Yarkovsky effect, considering both the Yarkovsky-Schach and planetary Yarkovsky components, and verify it against thermophysical numerical simulations. We find that the Yarkovsky force could change the mutual orbit when the asteroid's spin period is unequal to the orbital period. Our analysis predicts new evolutionary paths for binaries. For a prograde asynchronous secondary, the Yarkovsky force will migrate the satellite toward the location of the synchronous orbit on similar to 100 kyr timescales, which could be faster than other synchronization processes such as YORP and tides. For retrograde secondaries, the Yarkovsky force always migrates the secondary outward, which could produce asteroid pairs with opposite spin poles. Satellites spinning faster than the Roche limit orbit period (e.g., from similar to 4 hr to similar to 10 hr) will migrate inward until they disrupt, reshape, or form a contact binary. We also predict a short-lived equilibrium state for asynchronous secondaries where the Yarkovsky force is balanced by tides. We provide calculations of the Yarkovsky-induced drift rate for known asynchronous binaries. If the NASA DART impact broke Dimorphos from synchronous rotation, we predict that Dimorphos's orbit will shrink by a similar to 7 cm yr-1, which can be measured by the Hera mission. We also speculate that the Yarkovsky force may have synchronized the Dinkinesh-Selam system after a possible merger of Selam's two lobes.
Permanent Link: https://hdl.handle.net/11104/0354798