Cybele asteroid

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Cybele asteroids (also known as the "Cybeles") are a dynamical group of asteroids, named after the asteroid 65 Cybele.[1] Considered by some as the last outpost of an extended asteroid belt, the group consists of more than a thousand members and a few collisional families.[2][3]


The Cybeles are located adjacent to the outermost asteroid belt, beyond the Hecuba gap – the 2:1 resonance zone with Jupiter, where the Griqua asteroids are located – and inside the orbital region of the Hilda asteroids, which are themselves followed by the Jupiter trojans. The group is defined by an osculating semi-major axis of 3.28 to 3.70 AU,[2] with an eccentricity of less than 0.3, and an inclination less than 25°.[1]

Three secure collisional asteroid families exist within the Cybele group: the Sylvia family (603), the Huberta family and the Ulla family (903). A potential fourth family is a small cluster with the parent body (45657) 2000 EK.[2] A fifth family, named after 522 Helga, was identified in 2015.[3]

Some of the groups largest members include 87 Sylvia, 107 Camilla, 121 Hermione, 76 Freia, 790 Pretoria, and 566 Stereoskopia. Some of the group also have satellites, such as 87 Sylvia (Romulus and Remus), 107 Camilla and 121 Hermione.[1] The group is thought to have formed from the breakup of a larger object in the distant past.[1] While most members are C- and X-type asteroids, NASA's Wide-field Infrared Survey Explorer also measured albedos of some Cybele asteroids that are typical for stony S-type asteroids.[2]


Total of 1935 Cybeles with osculating semi-major axis between 3.28 and 3.7 AU. Low numbered members of the collisional Sylvia (SYL) and smaller Ulla (ULA) families are also marked.

See also[edit]


  1. ^ a b c d Elkins-Tanton, Linda T. (2010). "Asteroids, Meteorites, and Comets". p. 96. Retrieved 27 April 2018. 
  2. ^ a b c d Carruba, V.; Domingos, R. C.; Nesvorný, D.; Roig, F.; Huaman, M. E.; Souami, D. (August 2013). "A multidomain approach to asteroid families' identification" (PDF). Monthly Notices of the Royal Astronomical Society. 433 (3): 2075–2096. arXiv:1305.4847Freely accessible. Bibcode:2013MNRAS.433.2075C. doi:10.1093/mnras/stt884. Retrieved 27 April 2018. 
  3. ^ a b Carruba, V.; Nesvorný, D.; Aljbaae, S.; Huaman, M. E. (July 2015). "Dynamical evolution of the Cybele asteroids" (PDF). Monthly Notices of the Royal Astronomical Society. 451 (1): 244–256. arXiv:1505.03745Freely accessible. Bibcode:2015MNRAS.451..244C. doi:10.1093/mnras/stv997. Retrieved 27 April 2018.