24 Themis
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- For the spurious tenth satellite of Saturn, see Themis (hypothetical moon).
| Discovery | |
|---|---|
| Discovered by: | Annibale de Gasparis |
| Discovery date: | April 5, 1853 |
| Alternative names: | 1947 BA; 1955 OH |
| Minor planet category: | Main belt (Themis) |
| Orbital characteristics | |
| Epoch August 18, 2005 (JD 2453600.5) | |
| Aphelion distance: | 530.250 Gm (3.545 AU) |
| Perihelion distance: | 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) |
| Avg. 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 [5] |
| Temperature: | ~159 K |
| Spectral type: | C [4] (B-V=0.68) |
| Absolute magnitude: | 7.08 |
24 Themis (IPA: [ˈθimɪs]) is one of the largest Main belt asteroids. It is also the largest member of 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
- ^ http://www.psi.edu/pds/asteroid/EAR_A_5_DDR_ASTEROID_DENSITIES_V1_1
- ^ http://www.psi.edu/pds/archive/lc.html
- ^ http://www.astrosurf.com/aude-old/map_files/AstVarMAP01-2003.htm
- ^ http://pdssbn.astro.umd.edu/SBNcgi/sbdbatt?objnum=32124
- ^ http://ssd.jpl.nasa.gov/cgi-bin/da
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|---|---|---|
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| List of asteroids | ||
Vulcanoids · Near-Earth asteroids · Main belt · Jupiter Trojans · Centaurs · Damocloids · Comets · Trans-Neptunians (Kuiper belt • Scattered disc • Oort cloud)
For other objects and regions, see Asteroid groups and families, Binary asteroids, Asteroid moons and the Solar System.
For a complete listing, see List of asteroids. See also Pronunciation of asteroid names and Meanings of asteroid names.
