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.
.png) A three-dimensional model of 76 Freia based on its light curve. | |
| Discovery | |
|---|---|
| Discovered by | Heinrich d'Arrest |
| Discovery date | October 21, 1862 |
| Designations | |
| (76) Freia | |
| Pronunciation | /ˈfreɪ.ə/[1] |
Named after | Freyja |
| Outer main belt[2] (Cybele) | |
| Adjectives | Freian |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion | 594.715 Gm (3.975 AU) |
| Perihelion | 427.898 Gm (2.860 AU) |
| 511.306 Gm (3.418 AU) | |
| Eccentricity | 0.163 |
| 2307.979 d (6.32 a) | |
Average orbital speed | 16.00 km/s |
| 299.268° | |
| Inclination | 2.116° |
| 204.535° | |
| 254.070° | |
| Physical characteristics | |
| Dimensions | 183.7±4 km[2] |
| 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] | |
| CP | |
| 7.90 | |
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°±5°, 25°±5°).[4]
References
External links
- 76 Freia at AstDyS-2, Asteroids—Dynamic Site
- 76 Freia at the JPL Small-Body Database
