46 Hestia
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Discovery
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| Discovered by | Norman Robert Pogson |
| Discovery date | August 16, 1857 |
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Designations
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| Named after | Hestia |
| Alternate name(s) | |
| Minor planet category |
Asteroid belt |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion | 2.961 AU (442.886 Gm) |
| Perihelion | 2.091 AU (312.736 Gm) |
| Semi-major axis | 2.526 AU (377.811 Gm) |
| Eccentricity | 0.172 |
| Orbital period | 4.01 a (1465.958 d) |
| Average orbital speed | 18.60 km/s |
| Mean anomaly | 45.401° |
| Inclination | 2.342° |
| Longitude of ascending node | 181.168° |
| Argument of perihelion | 176.882° |
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Physical characteristics
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| Dimensions | 124.1 km[1] |
| Mass | 3.5×1018 kg[2] |
| Mean density | 3.5 g/cm³ |
| Equatorial surface gravity | 0.0347 m/s² |
| Escape velocity | 0.0656 km/s |
| Rotation period | 21.04 h[1] |
| Albedo | 0.052[1] |
| Temperature | ~175 K |
| Spectral type | C |
| Absolute magnitude (H) | 8.36[1] |
46 Hestia (
/ˈhɛstiə/) is a large, dark main-belt asteroid. It is also the primary body of the Hestia clump, a group of asteroids with similar orbits.
Hestia was discovered by N. R. Pogson on August 16, 1857, at the Radcliffe Observatory, Oxford. Pogson awarded the honour of naming it to William Henry Smyth, the previous owner of the telescope used for the discovery. Smyth chose to name it after Hestia, Greek goddess of the hearth.[3] This created a problem in Greek, where 4 Vesta also goes by the name Hestia.
Hestia has been studied by radar.[4]
[edit] Mass
In 2000, Michalak estimated Hestia to have a mass of 3.5×1018 kg.[2][5]
Even though Hestia is only about 124 km in diameter,[1] in 1997, Bange and Bec-Borsenberger estimated Hestia as having a mass of 2.1×1019 kg, based on a perturbation by 19 Fortuna.[6][7][8] This older 1997 estimate would give it a density of 14+ g/cm³[6] and make Hestia more massive than several much larger asteroids.
[edit] References
- ^ a b c d e f "JPL Small-Body Database Browser: 46 Hestia". 2008-06-28 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=46. Retrieved 2008-11-10.
- ^ a b Michalak, G. (2001). "Determination of asteroid masses". Astronomy & Astrophysics 374: 703–711. Bibcode 2001A&A...374..703M. doi:10.1051/0004-6361:20010731. http://www.aanda.org/index.php?option=article&access=standard&Itemid=129&url=/articles/aa/abs/2001/29/aa10228/aa10228.html. Retrieved 2008-11-10.
- ^ Schmadel, Lutz (2003). Dictionary of minor planet names (fifth ed.). Germany: Springer. p. 19. ISBN 3-540-00238-3. http://books.google.com/?id=KWrB1jPCa8AC&pg=PA19. Retrieved 2008-12-29.
- ^ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. http://echo.jpl.nasa.gov/asteroids/. Retrieved 2011-10-30.
- ^ (2000 mass estimate of 46 Hestia 0.018 / Mass of Ceres 4.75) * Mass of Ceres 9.43E+20 = 3.573E+18
- ^ a b Bange, J.F; A. Bec-Borsenberger (1997). DETERMINATION OF THE MASSES OF MINOR PLANETS. pp. 169. http://www.rssd.esa.int/Hipparcos/venice-proc/poster02_22.pdf. Retrieved 2008-11-10.
- ^ Baer, James; Steven R. Chesley (2007). "Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris" (PDF). Celestial Mechanics and Dynamical Astronomy (Springer Science+Business Media B.V. 2007) 100 (2008): 27–42. Bibcode 2008CeMDA.100...27B. doi:10.1007/s10569-007-9103-8. http://www.springerlink.com/content/h747307j43863228/fulltext.pdf. Retrieved 2008-11-10.
- ^ (Older mass estimate of Hestia 0.109 / Mass of Ceres 4.75) * Mass of Ceres 9.43E+20 = 2.163E+19
[edit] External links
- Orbital simulation from JPL (Java) / Ephemeris
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