132 Aethra
Discovery | |
---|---|
Discovered by | James C. Watson |
Discovery date | 13 June 1873 |
Designations | |
(132) Aethra | |
Pronunciation | /ˈiːθrə/ |
Named after | Aethra |
A922 XB; 1949 MD; 1953 LF | |
Mars crosser | |
Orbital characteristics[1] | |
Epoch 31 July 2016 (JD 2457600.5) | |
Uncertainty parameter 0 | |
Observation arc | 142.50 yr (52049 d) |
Aphelion | 3.6250 AU (542.29 Gm) |
Perihelion | 1.5895 AU (237.79 Gm) |
2.6073 AU (390.05 Gm) | |
Eccentricity | 0.39036 |
4.21 yr (1537.7 d) | |
Average orbital speed | 17.72 km/s |
38.271° | |
0° 14m 2.796s / day | |
Inclination | 24.997° |
258.408° | |
255.216° | |
Physical characteristics | |
Dimensions | 35.83±6.59 km[2] 42.87±1.6 km[1] |
Mass | (0.41±2.71)×1018 kg[2] |
Mean density | 17 g/cm3[2] |
5.1684 h (0.21535 d)[1] | |
0.1990±0.015[1] | |
M | |
9.38[1] | |
132 Aethra is a metallic asteroid and Mars-crosser on an eccentric orbit from the asteroid belt. It measures approximately 40 kilometers in diameter.
It was discovered by James Craig Watson in 1873 and is 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. It has a rather eccentric orbit that sometimes brings it closer to the Sun than the planet Mars.
With an original observation arc of only 22 days, 132 Aethra was a lost asteroid between 1873 and 1922.[3][4]
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.
References
- ^ a b c d e "JPL Small-Body Database Browser: 132 Aethra" (2000-06-10 last obs). Retrieved 12 May 2016.
- ^ a b c Carry, B. (December 2012). "Density of asteroids" (PDF). Planetary and Space Science. 73 (1): 98–118. arXiv:1203.4336. Bibcode:2012P&SS...73...98C. doi:10.1016/j.pss.2012.03.009. Retrieved 2 November 2017. See Table 1.
- ^ Herget, 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)
External links