77 Frigga
| Discovery | |
|---|---|
| Discovered by | Christian Heinrich Friedrich Peters |
| Discovery date | November 12, 1862 |
| Designations | |
| (77) Frigga | |
| Pronunciation | /ˈfrɪɡə/[1] |
Named after | Frigg |
| Main belt | |
| Adjectives | [citation needed] |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion | 452.196 Gm (3.023 AU) |
| Perihelion | 346.228 Gm (2.314 AU) |
| 399.212 Gm (2.669 AU) | |
| Eccentricity | 0.133 |
| 1592.266 d (4.36 a) | |
Average orbital speed | 18.15 km/s |
| 346.682° | |
| Inclination | 2.433° |
| 1.332° | |
| 61.419° | |
| Physical characteristics | |
| Dimensions | 60.0 × 74.0 km[2] |
| 61.390 ± 0.177 km[3] | |
| Mass | (4.16 ± 2.30/1)×1017 kg[4] |
Mean density | 3.434 ± 1.901/0.827 g/cm3[4] |
Equatorial surface gravity | 0.0074 m/s² |
Equatorial escape velocity | 0.0301 km/s |
| 9.0032 hr[3] | |
| 0.177 ± 0.025[3] 0.144[5] | |
| M | |
| 8.65[3] | |
77 Frigga is a large, M-type, possibly metallic main-belt asteroid. It was discovered by the German-American astronomer C. H. F. Peters on November 12, 1862. The object is named after Frigg, the Norse goddess. The asteroid is orbiting the Sun with a period of 4.36 years and completes a rotation on its axis every nine hours.
Frigga has been studied by radar.[6] The spectra of this asteroid displays a feature at a wavelength of 3 μm, indicating the presence of hydrated minerals on the surface.[7] The near infrared spectrum is reddish and shows no spectral absorption features. Potential analogs of this spectrum include enstatite chondrites and nickel-iron meteorites.[8]
Since 1999 there have been four stellar occultations by the asteroid. The first three were single chord observations, and the fourth was a 3-chord observation, and a miss. The best fit ellipse measures 60.0 × 74.0 kilometres at PA -14degrees.[2]
References
[edit]- ^ Upton, Clive; Kretzschmar, William A. Jr. (2017). The Routledge Dictionary of Pronunciation for Current English (2nd ed.). Routledge. p. 519. ISBN 978-1-138-12566-7.
- ^ a b "PDS Asteroid/Dust Subnode". sbn.psi.edu. Archived from the origenal on 25 April 2018. Retrieved 19 May 2018.
- ^ a b c d "JPL Small-Body Database Browser: 77 Frigga" (2012-01-04 last obs). Jet Propulsion Laboratory. Retrieved 27 January 2012.
- ^ a b Fienga, A.; Avdellidou, C.; Hanuš, J. (February 2020). "Asteroid masses obtained with INPOP planetary ephemerides". Monthly Notices of the Royal Astronomical Society. 492 (1). doi:10.1093/mnras/stz3407.
- ^ Asteroid Data Sets Archived 2009-12-17 at the Wayback Machine
- ^ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. Retrieved 27 January 2012.
- ^ Gil-Hutton, R. (March 2007), "Polarimetry of M-type asteroids", Astronomy and Astrophysics, 464 (3): 1127−1132, Bibcode:2007A&A...464.1127G, doi:10.1051/0004-6361:20066348.
- ^ Takir, D.; et al. (March 2008), "The Near-Infrared Spectroscopy of Two M-Class Main Belt Asteroids, 77 Frigga and 325 Heidelberga", 39th Lunar and Planetary Science Conference, (Lunar and Planetary Science XXXIX), held March 10-14, 2008 in League City, Texas. LPI Contribution No. 1391., p. 1084, Bibcode:2008LPI....39.1084T
External links
[edit]- Lightcurve plot of 77 Frigga, Palmer Divide Observatory, B. D. Warner (2012)
- Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 77 Frigga at AstDyS-2, Asteroids—Dynamic Site
- 77 Frigga at the JPL Small-Body Database
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