65 Cybele (pronounced /ˈsɪbɨliː/ SIB-əl-ee, or as in Greek Κυβέλη) is one of the largest asteroids in the main belt. It gives its name to the Cybele asteroids which orbit outward from the Sun from the 2:1 orbital resonance with Jupiter. As a C-type asteroid it is dark in color and carbonaceous in composition. It was discovered on March 8, 1861 by Ernst Tempel and named after Cybele the earth goddess.

The first Cybelian stellar occultation was observed on October 17, 1979 in the Soviet Union. The asteroid appeared to have an irregular shape, with the longest chord being measured as 245 km, closely matching the diameter of 237 km determined by the IRAS satellite. During the same occultation, a hint of a possible 11 km wide satellite was detected.[4]

In 1985, Green estimated Cybele to have a diameter of 330 km.[2] In 2004, Müller estimated Cybele using thermophysical modelling (TPM) to have dimensions of 302×290×232 km.[2] The diameter from IRAS observations as listed on JPL was 237.26 km (118.63 km radius).[1]

2009 occultation

On October 11, 2009, Cybele was expected to occult a 13.4 magnitude star in the constellation Aquarius.[5]

References

1. ^ a b c d e f "JPL Small-Body Database Browser: 65 Cybele". 2008-08-10 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=65. Retrieved 2008-11-25.
2. ^ a b c d e Müller, T. G; Blommaert, J. A. D. L. (2004). "65 Cybele in the thermal infrared: Multiple observations and thermophysical analysis". Astronomy and Astrophysics 418: 347–356. doi:10.1051/0004-6361:20040025.
3. ^ a b Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. http://home.earthlink.net/~jimbaer1/astmass.txt. Retrieved 2008-11-28.
4. ^ "IAUC 3439: 1979l; Occn OF AGK3 +19 599 BY (65)". MPC (Circular No. 3439). 1980-01-04. http://www.cfa.harvard.edu/iauc/03400/03439.html. Retrieved 2004-06-18.
5. ^ Steve Preston. "(65) Cybele / 2UCAC 28838190 event on 2009 Oct 11, 01:30 UT". http://www.asteroidoccultation.com/2009_10/1011_65_22846_Summary.txt. Retrieved 2009-09-21.

External links

* Orbital simulation from JPL (Java) / Ephemeris