132 Aethra
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Discovery
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| Discovered by | James C. Watson |
| Discovery date | June 13, 1873 |
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Designations
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| Named after | Aethra |
| Alternate name(s) | A922 XB; 1949 MD; 1953 LF |
| Minor planet category |
Main belt (Mars crosser) |
| Epoch July 14, 2004 (JD 2453200.5) | |
| Aphelion | 541.841 Gm (3.622 AU) |
| Perihelion | 238.558 Gm (1.595 AU) |
| Semi-major axis | 390.199 Gm (2.608 AU) |
| Eccentricity | 0.389 |
| Orbital period | 1538.652 d (4.21 a) |
| Average orbital speed | 17.72 km/s |
| Mean anomaly | 89.813° |
| Inclination | 25.055° |
| Longitude of ascending node | 258.945° |
| Argument of perihelion | 254.330° |
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Physical characteristics
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| Dimensions | 42.87 km[1] |
| Mass | 8.2×1016 kg |
| Mean density | 2 ? g/cm³ |
| Equatorial surface gravity | 0.012 m/s² |
| Escape velocity | 0.023 km/s |
| Rotation period | 0.2153 d (5.168 h)[1] |
| Albedo | 0.199[1] |
| Temperature | ~168 K |
| Spectral type | M |
| Absolute magnitude (H) | 9.21[1] |
Discovered by James Craig Watson in 1873, 132 Aethra is an M-type main-belt asteroid. It has a rather eccentric orbit that sometimes brings it closer to the Sun than the planet Mars. It was the first such Mars-crosser asteroid to be identified. As a Mars-crosser asteroid, Aethra is the lowest numbered asteroid to not have proper orbital elements due to recurring perturbations by Mars.
With an original observation arc of only 22 days, 132 Aethra was a lost asteroid between 1873 and 1922.[2][3]
The varying light curve of the asteroid implies an elongated or irregular shape for its body.
It is named after Aethra, the mother of Theseus in Greek mythology.
[edit] References
- ^ a b c d e "JPL Small-Body Database Browser: 132 Aethra". 2000-06-10 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=132. Retrieved 2008-11-30.
- ^ Herge, Paul (1938). "The orbit and perturbations of (132) Aethra". Astronomical Journal 47 (1081): 17–23. Bibcode 1938AJ.....47...17H. doi:10.1086/105455.
- ^ The planet observer's handbook (2000), By Fred William Price, Page 192. (Google Books 2010)
[edit] External links
- Orbital simulation from JPL (Java) / Ephemeris
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