Spin axis of (2953) Vysheslavia and its implications

Abstract Photometric observations made during the years 2000–2005 are used to determine the pole orientation of (2953) Vysheslavia, a ≃15-km size member of the Koronis family. We find admissible solutions for ecliptic latitude and longitude of the rotation pole P 3 : β p = − 64 ° ± 10 ° and λ p = 11 ° ± 8 ° or P 4 : β p = − 68 ° ± 8 ° and λ p = 192 ° ± 8 ° . These imply obliquity values γ = 154 ° ± 14 ° and γ = 157 ° ± 11 ° , respectively. The sidereal rotation period is P sid = 0.2622722 ± 0.0000018 day . This result is interesting for two reasons: (i) the obliquity value between 90° and 180° is consistent with a prediction done by Vokrouhlický et al. [Vokrouhlický, D., Brož, M., Farinella, P., Kneževic, Z., 2001. Icarus 150, 78–93] that Vysheslavia might have been transported to its unstable orbit by the Yarkovsky effect, and (ii) with the obliquity close to 180°, Vysheslavia seems to belong to one of the two distinct groups in the Koronis family found recently by Slivan [Slivan, S.M., 2002. Nature 419, 49–51], further supporting the case of dichotomy in the spin axis distribution in this family. We also argue against the possibility that Vysheslavia reached its current orbit by a recent collisional breakup.