Shape model and spin state of non-principal axis rotator (5247) Krylov

Autor: Lee, H. -J., Ďurech, J., Kim, M. -J., Moon, H. -K., Kim, C. -H., Choi, Y. -J., Galád, A., Pray, D., Marciniak, A., Kaplan, M., Erece, O., Duffard, R., Gajdoš, Š., Világi, J., Lehký, M.
Rok vydání: 2020
Předmět:
Zdroj: A&A 635, A137 (2020)
Druh dokumentu: Working Paper
DOI: 10.1051/0004-6361/201936808
Popis: Context. The study of non-principal axis (NPA) rotators can provide important clues to the evolution of the spin state of asteroids. However, so far, very few studies have focused on NPA-rotating main-belt asteroids (MBAs). One of MBAs that are known to be in an excited rotation state is asteroid (5247) Krylov. Aims. By using disk-integrated photometric data, we construct a physical model of (5247) Krylov including shape and spin state. Methods. We apply the light curve convex inversion method employing optical light curves obtained by using ground-based telescopes in three apparitions during 2006, 2016, and 2017, along with infrared light curves obtained by the Wide-field Infrared Survey Explorer (WISE) satellite in 2010. Results. Asteroid (5247)~Krylov is spinning in a short axis mode (SAM) characterized by rotation and precession periods of 368.7 hr and 67.27 hr, respectively. The angular momentum vector orientation of Krylov is found to be $\lambda_{L} = 298^\circ$ and $\beta_{L} = -58^\circ$. The ratio of the rotational kinetic energy to the basic spin state energy $E/E_{0} \simeq 1.02$ shows that the (5247) Krylov is about 2% excited state compared to the Principal Axis (PA) rotation state. The shape of (5247) Krylov can be approximated by an elongated prolate ellipsoid with a ratio of moments of inertia of $I_{a}:I_{b}:I_{c}=0.36:0.96:1$. This is the first physical model of NPA rotator among MBAs. The physical processes that led to the current NPA rotation cannot be unambiguously reconstructed.
Comment: 10 pages, 2 figures; Accepted for publication on Astronomy & Astrophysics
Databáze: arXiv
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