Astronomy:77 Frigga
| Discovery | |
|---|---|
| Discovered by | Christian Heinrich Friedrich Peters |
| Discovery date | November 12, 1862 |
| Designations | |
| (77) Frigga | |
| Pronunciation | /ˈfrɪɡə/[1] |
| Named after | Frigg |
| Minor planet category | Main belt |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| |{{{apsis}}}|helion}} | 452.196 Gm (3.023 AU) |
| |{{{apsis}}}|helion}} | 346.228 Gm (2.314 AU) |
| 399.212 Gm (2.669 AU) | |
| Eccentricity | 0.133 |
| Orbital period | 1592.266 d (4.36 a) |
| Average Orbital speed | 18.15 km/s |
| Mean anomaly | 346.682° |
| Inclination | 2.433° |
| Longitude of ascending node | 1.332° |
| 61.419° | |
| Physical characteristics | |
| Dimensions | 60.0 × 74.0 km[2] |
| Mean diameter | 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 |
| Rotation period | 9.0032 hr[3] |
| Geometric albedo | 0.177 ± 0.025[3] 0.144[5] |
| M | |
| Absolute magnitude (H) | 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]
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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
- ↑ Template:Cite RDPCE
- ↑ 2.0 2.1 "PDS Asteroid/Dust Subnode" (in en). https://sbn.psi.edu/pds-staging/resource/occ.html.
- ↑ 3.0 3.1 3.2 3.3 "JPL Small-Body Database Browser: 77 Frigga". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=77.
- ↑ 4.0 4.1 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. https://academic.oup.com/mnras/article/492/1/589/5658701.
- ↑ Asteroid Data Sets
- ↑ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. http://echo.jpl.nasa.gov/asteroids/.
- ↑ Gil-Hutton, R. (March 2007), "Polarimetry of M-type asteroids", Astronomy and Astrophysics 464 (3): 1127−1132, doi:10.1051/0004-6361:20066348, Bibcode: 2007A&A...464.1127G.
- ↑ 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
- Lightcurve plot of 77 Frigga, Palmer Divide Observatory, B. D. Warner (2012)
- Asteroid Lightcurve Database (LCDB), query form (info )
- 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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