Themis family


The Themis family (adj. Themistian; FIN: 602) is a family of carbonaceous asteroids located in the outer portion of the asteroid belt, at a mean distance of 3.13 AU from the Sun. It is one of the largest families with over 4700 known members,[1] and consists of a well-defined core of larger bodies surrounded by a region of smaller ones. The collisional Themis family is named after its parent body, the asteroid 24 Themis, discovered on 5 April 1853 by Italian astronomer Annibale de Gasparis.[2]


The Themis family is one of the largest and longest-recognized dynamical families of asteroids, and is made up of C-type asteroids with a composition believed to be similar to that of carbonaceous chondrites.[3] To date, the Themis family comprises approximately 535 known asteroids.

Asteroids in the Themis family share the following orbital elements:

  • semimajor axes between 3.08 AU and 3.24 AU
  • orbital eccentricities between 0.09 and 0.22
  • orbital inclinations of less than 3°


Some of the largest members of this family include:[4][5]

See also


  1. ^ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). Identification and Dynamical Properties of Asteroid Families. Asteroids IV. pp. 297–321. arXiv:1502.01628. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.
  2. ^ "24 Themis". Minor Planet Center. Retrieved 7 November 2018.
  3. ^ DIVERSITY OF TYPES OF HYDRATED MINERALS ON C≠CLASS ASTEROIDS A. S. Rivkin, Massachusetts Institute of Technology, E. S. Howell, Arecibo Observatory, S. J. Bus, Institute for Astronomy
  4. ^ de León, J.; Pinilla-Alonso, N.; Campins, H.; Licandro, J.; Marzo, G. A. (March 2012). "Near-infrared spectroscopic survey of B-type asteroids: Compositional analysis". Icarus. 218 (1): 196–206. Bibcode:2012Icar..218..196D. doi:10.1016/j.icarus.2011.11.024. Retrieved 7 November 2018.
  5. ^ Licandro, J.; Hargrove, K.; Kelley, M.; Campins, H.; Ziffer, J.; Alí-Lagoa, V.; et al. (January 2012). "5-14 mum Spitzer spectra of Themis family asteroids" (PDF). Astronomy and Astrophysics. 537: 7. Bibcode:2012A&A...537A..73L. doi:10.1051/0004-6361/201118142. Retrieved 7 November 2018.
  • Castillo-Rogez, C. & Schmidt, B. E. (2010). "Geophysical Evolution of the Themis Family Parent Body" (PDF). Cite journal requires |journal= (help)

External links

  • Nesvorny HCM Asteroid Families V3.0, Small Bodies Data Ferret