29 Amphitrite
From Wikipedia, the free encyclopedia
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Discovery
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| Discovered by | A. Marth |
| Discovery date | March 1, 1854 |
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Designations
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| Alternative names | A899 NG |
| Minor planet category |
Main belt |
| Epoch June 14, 2006 (JD 2453900.5) | |
| Aphelion | 409.809 Gm (2.739 AU) |
| Perihelion | 354.398 Gm (2.369 AU) |
| Semi-major axis | 382.103 Gm (2.554 AU) |
| Eccentricity | 0.073 |
| Orbital period | 1491.013 d (4.08 a) |
| Average orbital speed | 18.61 km/s |
| Mean anomaly | 229.662° |
| Inclination | 6.096° |
| Longitude of ascending node | 356.501° |
| Argument of perihelion | 63.433° |
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Physical characteristics
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| Dimensions | 212.2 km † |
| Mass | 1.0×1019 kg |
| Mean density | 2.0 g/cm³ |
| Equatorial surface gravity | 0.0593 m/s² |
| Escape velocity | 0.1122 km/s |
| Rotation period | 0.2246 d (5.390 h) [1] |
| Albedo | 0.1793 (geometric) [2] |
| Temperature | ~170 K |
| Spectral type | S |
| Apparent magnitude | 8.58 to 11.38 |
| Absolute magnitude | 5.85 |
| Angular diameter | 0.21" to 0.078" |
29 Amphitrite (pronounced /ˌæmfɪˈtraɪti/, Greek: Αμφιτρίτη) is one of the largest 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 larger cousins - being indeed the most circular of any asteroid discovered up to that point - and as a consequence it never becomes as bright as Iris or Hebe, especially as it is much further 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 discovered by Albert Marth on March 1, 1854. It was his only asteroid discovery. It is named after Amphitrite, a sea goddess in Greek mythology.
A satellite is suspected based on the lightcurve data.[1] [2]
[edit] References
- ^ Tedesco, E. F. (March 1979). "Binary Asteroids: Evidence for Their Existence from Lightcurves". Science, New Series 203 (4383): 905-907.
- ^ van Flandern, T. C.; Tedesco, E. F.; Binzel, R. P. (1979). "Satellites of asteroids". 'Asteroids': 443-465, Tucson, AZ: University of Arizona Press.
[edit] External links
- Orbital simulation from JPL (Java) / Ephemeris
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