Spins and shapes of V-type asteroids outside the dynamical Vesta family

Oszkiewicz, Dagmara; Troianskyi, Volodymyr; Wilawer, Emil; Galad, Adrian; Marciniak, Anna; Skiff, Brian; Fohring, Dora; Polakis, Tom; Geier, Stefan; Kwiatkowski, Tomasz; Kolenczuk, Paweł; Moskovitz, Nicholas; Benishek, Vladimir; Pray, Donald; Shevchenko, Vasilij; Kankiewicz, Paweł; Hasegawa, Sunao
Bibliographical reference

European Planetary Science Congress

Advertised on:
9
2022
Description
Vast majority of known V-type asteroids belong to the dynamical Vesta family. A small number of V-types in the mid and outer parts of the Main Asteroid Belt is considered unrelated to the fossil planetesimal (4) Vesta. These objects have low probability of dynamically evolving from the Vesta family and show spectral properties distinct from typical Vestoids [1-7]. Whether there are V-types unrelated to Vesta (non-Vestoids) in the inner part of the Main Asteroid Belt is still an open question. To answer it, we performed a large and long-lasting observing campaign of V-types in the inner Main Belt outside the dynamical Vesta family [8,9]. We determine their rotational properties and compare them with the numerical simulations made by Nesvorny et al. 2008. According to that study 81% of objects evolving from the Vesta family to so-called Cell I (defined by orbital elements 2.2 au<a<2.3 au, 0.05<e<0.2, 0 deg <i<10 deg) and 40% to Cell II (2.32 au <a<2.48 au, 0.05<e<0.2, 2 deg<i< 6 deg) should have retrograde rotations. We observed a total of 23 asteroids larger than 5 km in diameter in both of those Cells over multiple apparitions. We determined spins and shapes for 13 of them so far. In Cell I we found only retrograde objects and in Cell II 6 prograde and 2 retrograde objects. With the complete sample we plan to put constraints on the distribution of possible non-Vestoids in the inner Main Belt.[1] Lazzaro, D. et al., 2000, Science 288, 2033-2035.[2] Hardersen et al., 2004, 167, Icarus 170-177[3] Michtchenko et al., 2002, Icarus 158, 343-359.[4] Fulvio, D. et al, 2018, Planetary and Space Science 164, 37-43.[5] Ieva, et al. 2016, Monthly Notices of the Royal Astronomical Society 455, 2871-2888.[6] Ieva, S.et al., 2018, Monthly Notices of the Royal Astronomical Society 479, 2607-2614.[7] Roig, F. et al. 2008, Icarus 194, 125-136.[8] Oszkiewicz, D., et al., 2020, Astronomy & Astrophysics 643, A117[9] Oszkiewicz, D. et al., 2021, Icarus 357, 114158.[10] Nesvorný, D., et al., 2008, Icarus 193, 85-95.