76 Freia
.png) A three-dimensional model of 76 Freia based on its light curve | |
| Discovery | |
|---|---|
| Discovered by | Heinrich d'Arrest |
| Discovery date | 21 October 1862 |
| Designations | |
| Pronunciation | /ˈfreɪ.ə/ |
Named after | Freyja |
| Outer main belt (Cybele) | |
| Adjectives | Freian |
| Orbital characteristics | |
| Epoch 9 June 2026 (JD 2461200.5) | |
| Uncertainty parameter 0 | |
| Aphelion | 3.9800 AU |
| Perihelion | 2.8368 AU |
| 3.4084 AU | |
| Eccentricity | 0.1677 |
| 2298.41 d (6.2927 yr) | |
Average orbital speed | 16.00 km/s |
| 330.760° | |
| Inclination | 2.1236° |
| 204.271° | |
| 252.284° | |
| TJupiter | 3.121 |
| Physical characteristics | |
| Dimensions | 167.87±8.73 km (composite estimate) 183.7±4 km |
| Mass | (3.09±0.51)×1018 kg |
Mean density | 1.92 g/cm3 |
Equatorial surface gravity | 0.0513 m/s2 |
Equatorial escape velocity | 0.0971 km/s |
| 9.968240±0.000009 h | |
| 0.036 | |
| CP | |
| 7.90 | |
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. Its composition is very primitive and it is extremely dark in color. Freia was discovered by the astronomer Heinrich d'Arrest on 21 October 1862, in Copenhagen, Denmark. It was his first and only asteroid discovery. It is named after the goddess Freyja in Norse mythology.
It is orbiting the Sun at a distance of 3.42 AU with a moderate eccentricity (ovalness) of 0.16 and an orbital period of 6.32 years. The orbital plane is inclined at an angle of 2.116° relative to the plane of the ecliptic. Based on infrared measurements, it has a diameter of 184 km. The asteroid has a Tholen spectral type of P.
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. 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°).
Notes
- ↑ Calculated from its standard gravitational parameter GM = 0.206±0.034 km3/s2.
- ↑ Assuming a diameter of 145 km.
References
- ↑ "Freya". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 22 March 2020.
- 1 2 3 4 "JPL Small-Body Database Browser: 76 Freia" (2008-03-04 last obs). Retrieved 5 September 2010.
- ↑ Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73 (1): 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009, S2CID 119226456. See Table 1.
- 1 2 Fuentes-Muñoz, Oscar; Farnocchia, Davide; Giorgini, Jon D.; Park, Ryan S. (1 December 2025). "Asteroid Mass Estimation by Mutual Perturbations During Close Encounters After Gaia Focused Product Release". The Astronomical Journal. 170 (6): 353. Bibcode:2025AJ....170..353F. doi:10.3847/1538-3881/ae0cc9. ISSN 0004-6256. S2CID 283347135.
- 1 2 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.
- ↑ Asteroid Data Sets Archived 2009-12-17 at the Wayback Machine
- ↑ 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, S2CID 119383924.
- ↑ 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.
External links
- 76 Freia at AstDyS-2, Asteroids—Dynamic Site
- 76 Freia at the JPL Small-Body Database
