Dynamical evolution of basaltic asteroids outside the Vesta family in the inner main belt

Abstract

Context. Basaltic V-type asteroids are leftovers from the formation and evolution of differentiated planetesimals. They are thought to originate from mantles and crusts of multiple different parent bodies. Identifying the links between individual V-type asteroids and multiple planetesimals is challenging, especially in the inner part of the main asteroid belt, where the majority of V-type asteroids are expected to have originated from a single planetesimal, namely, (4) Vesta. Aims. In this work, we aim to trace the origin of a number of individual V-type asteroids from the inner part of the main asteroid belt. The main goal is to identify asteroids that may not be traced back to (4) Vesta and may therefore originate from other differentiated planetesimals. Methods. We performed a 2 Gyr backward numerical integration of the orbits of the selected V-type asteroids. For each asteroid, we used 1001 clones to map the effect of orbital uncertainties. In the integration, we use information on physical properties of the considered V-type asteroids such as pole orientation, rotational period, and thermal parameters. Results. The majority of the studied objects can be traced back to the Vesta family within 2 Gyr of integration. The number of objects of the low-inclination V-types did not reach the boundary of the Vesta family during the integration time. Two asteroids, namely, (3307) Athabasca and (17028) 1999 FJ5, do not show a dynamic link to (4) Vesta. Increasing the integration time for these objects leads to further separation from (4) Vesta. Conclusions. The majority of V-types in the inner main belt outside the Vesta family are clearly Vesta fugitives. Two objects, namely, (3307) Athabasca and (17028) 1999 FJ5, show no clear dynamical link to (4) Vesta. Together with (809) Lundia (from our previous work), these objects could represent the parent bodies of anomalous HED meteorites such as the Banbura Rockhole. Furthermore, some objects of the low-inclination population cannot be traced back to (4) Vesta within the 2 Gyr integration.

First reported observation of asteroids 2017 AB8, 2017 QX33, and 2017 RV12

“…Astrometric observations are very important for further research (numerical integration of orbits) of small bodies of the Solar System (Troianskyi & Bazyey, 2018;Troianskyi et al, 2023).…”

Accretion and Uneven Depletion of the Main Asteroid Belt

“…We do not consider N = 2 or 3 as an at least marginally successful outcome for two main reasons. First, although the existence of Vesta-like fragments (basaltic objects with V-type taxonomy) that do not show a direct orbital link to (4) Vesta and its family suggest the existence of other V-type parent bodies (e.g., Brasil et al 2017;Burbine et al 2023;Troianskyi et al 2023), we have no information about their possible origin and size. Therefore, these hypothetical additional V-type parent bodies could likely be much smaller than our D = 500 km size limit.…”

Temporary capture of a small body into a geocentric orbit

“…To account for the influence of the light pressure, the following parameters were assigned: R = 100 m, m i = 4.2×10 9 kg = 2.1×10 −21 m 0 , ρ = 1000 kg m −3 , θ = 7.5×10 −6 m 2 kg −1 , a gr = 5.9×10 −3 m s −2 , κ = 1 (Troianskyi & Bazyey, 2018;Troianskyi et al, 2023).…”