Discovery | |
---|---|
Discovered by | A. Marth |
Discovery date | March 1, 1854 |
Designations | |
A899 NG | |
Main belt | |
Orbital characteristics | |
Epoch June 14, 2006 (JD 2453900.5) | |
Aphelion | 409.809 Gm (2.739 AU) |
Perihelion | 354.398 Gm (2.369 AU) |
382.103 Gm (2.554 AU) | |
Eccentricity | 0.073 |
1491.013 d (4.08 a) | |
Average orbital speed | 18.61 km/s |
229.662° | |
Inclination | 6.096° |
356.501° | |
63.433° | |
Physical characteristics | |
Dimensions | 212.2 km |
Mass | 1.0×1019 kg |
Mean density | 2.0 g/cm³ |
0.0593 m/s² | |
0.1122 km/s | |
0.2246 d (5.390 h) [1] | |
Albedo | 0.1793 (geometric) [2] |
Temperature | ~170 K |
Spectral type | S |
8.58 to 11.38 | |
5.85 | |
0.21" to 0.078" | |
29 Amphitrite is one of the biggest S-type asteroids, probably third in diameter after Eunomia and Juno, although Iris and Herculina are similar in size.
It is probably not a fully solid body, since its density is too low for a solid silicate object and much lower than Eunomia or Juno. Its orbit is less eccentric and inclined than those of its bigger cousins - being indeed the most circular of any asteroid found up to that point - and as a consequence it never becomes as bright as Iris or Hebe, especially as it is much farther from the Sun than those asteroids. It can reach magnitudes of around +8.6 at a favorable opposition, but more usually is around the binocular limit of +9.5.
Amphitrite was found by Albert Marth on March 1, 1854. It was the only asteroid he found. It is named after Amphitrite, a sea goddess in Greek mythology.
A moon is suspected based on the lightcurve data.[3] [4]