(76) Freia

76 Freia
76Freia (Lightcurve Inversion).png
A three-dimensional model of 76 Freia based on its light curve.
Discovered byHeinrich d'Arrest
Discovery dateOctober 21, 1862
(76) Freia
Named after
Outer main belt[1] (Cybele)
Orbital characteristics
Epoch December 31, 2006 (JD 2454100.5)
Aphelion594.715 Gm (3.975 AU)
Perihelion427.898 Gm (2.860 AU)
511.306 Gm (3.418 AU)
2307.979 d (6.32 a)
16.00 km/s
Physical characteristics
Dimensions183.7±4 km[1]
Mass(1.97 ± 4.20) × 1018 kg[3]
Mean density
0.79 ± 1.69[3] g/cm3
Equatorial surface gravity
0.0513 m/s2
Equatorial escape velocity
0.0971 km/s
9.968240±0.000009 h[4]
0.036 [5]

Freia (minor planet designation: 76 Freia) is a very large main-belt asteroid. It orbits in the outer part of the asteroid belt and is classified as a Cybele asteroid.[6] Its composition is very primitive and it is extremely dark in color. Freia was discovered by the astronomer Heinrich d'Arrest on October 21, 1862, in Copenhagen, Denmark. It was his first and only asteroid discovery. It is named after the goddess Freyja in Norse mythology.

The sidereal orbital period of this asteroid is commensurable with that of Jupiter, which made it useful for ground-based mass estimates of the giant planet.[7] A shape model for the asteroid was published by Stephens and Warner (2008), based upon lightcurve data. This yielded a sidereal rotation period of 9.968240±0.000009 h. They found two possible solutions for the spin axis, with the preferred solution in ecliptic coordinates being (λ, β) = (139°±, 25°±).[4]


  1. ^ a b "JPL Small-Body Database Browser: 76 Freia" (2008-03-04 last obs). Retrieved 5 September 2010.
  2. ^ "Freya". Lexico UK Dictionary. Oxford University Press.
  3. ^ a b Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
  4. ^ a b Stephens, Robert D.; Warner, Brian D. (June 2008), "A Preliminary Shape and Spin Axis Model for 76 Freia", The Minor Planet Bulletin, 35 (2): 84−85, Bibcode:2008MPBu...35...84S.
  5. ^ Asteroid Data Sets Archived 2009-12-17 at the Wayback Machine
  6. ^ De Prá, M. N.; et al. (September 2018), "PRIMASS visits Hilda and Cybele groups", Icarus, 311: 35–51, arXiv:1711.02071, Bibcode:2018Icar..311...35D, doi:10.1016/j.icarus.2017.11.012.
  7. ^ Klepczynski, W. J.; et al. (November 1971), "The Mass of Jupiter from the Motion of (76) Freia", Astronomical Journal, 76: 939, Bibcode:1971AJ.....76..939K, doi:10.1086/111204.

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