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]