24 Themis
From Wikipedia, the free encyclopedia
For the spurious tenth satellite of Saturn, see Themis (hypothetical moon).
|
Discovery
|
|
|---|---|
| Discovered by | Annibale de Gasparis |
| Discovery date | April 5, 1853 |
|
Designations
|
|
| Alternative names | 1947 BA; 1955 OH |
| Minor planet category |
Main belt (Themis) |
| Epoch August 18, 2005 (JD 2453600.5) | |
| Aphelion | 530.250 Gm (3.545 AU) |
| Perihelion | 406.202 Gm (2.715 AU) |
| Semi-major axis | 468.226 Gm (3.130 AU) |
| Eccentricity | 0.132 |
| Orbital period | 2022.524 d (5.54 a) |
| Average orbital speed | 16.76 km/s |
| Mean anomaly | 185.968° |
| Inclination | 0.760° |
| Longitude of ascending node | 35.992° |
| Argument of perihelion | 107.989° |
|
Physical characteristics
|
|
| Dimensions | 198 km [1] |
| Mass | 5.75±2.51×1019 kg [1] |
| Mean density | 14±6 g/cm³ doubtful |
| Equatorial surface gravity | 0.39±0.27 m/s² |
| Escape velocity | 0.88±0.22 km/s |
| Rotation period | 0.34892 d (8 h 23 min) [2][3] |
| Albedo | 0.067 [4] |
| Temperature | ~159 K |
| Spectral type | C [5] (B-V=0.68) |
| Absolute magnitude | 7.08 |
24 Themis (pronounced /ˈθiːmɪs/, Greek: Θέμις) is one of the largest Main belt asteroids. It is also the largest member of the Themistian asteroid family.
It was discovered by Annibale de Gasparis on April 5, 1853. The mass and diameter appearing in the table are from separate sources, and combining them gives an unusually large density, which is most probably wrong. The mass has very likely been overestimated by a factor of at least five times.
It is named after Themis, the personification of divine order, law and custom in Greek mythology.
[edit] References
- ^ Index of /pds/asteroid/EAR_A_5_DDR_ASTEROID_DENSITIES_V1_1
- ^ [1][dead link]
- ^ [2][dead link]
- ^ Page Modified
- ^ Small Bodies Attributes Utility Results
|
|||||
