Summary
Aethra (minor planet designation: 132 Aethra) is a metallic asteroid and Mars-crosser on an eccentric orbit from the asteroid belt. It measures approximately 40 kilometers in diameter.
 Lightcurve-based 3D-model of Aethra | |
| Discovery | |
|---|---|
| Discovered by | James C. Watson |
| Discovery date | 13 June 1873 |
| Designations | |
| (132) Aethra | |
| Pronunciation | /ˈiːθrə/[1] |
Named after | Aethra |
| A873 LA; 1922 XB; 1949 MD; 1953 LF | |
| Mars crosser | |
| Orbital characteristics[2] | |
| 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 | |
Mean diameter | 42.87±1.6 km[2] 44.47±0.74 km[3] |
| Mass | (1.59 ± 0.89/0.42)×1017 kg[3] |
Mean density | 3.447 ± 1.935/0.923 g/cm3[3] |
| 5.1684 h (0.21535 d)[2] | |
| 0.1990±0.015[2] | |
| M | |
| 8.96[2] | |
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.[4][5]
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 edit
- ^ Noah Webster (1884) A Practical Dictionary of the English Language
- ^ a b c d e "JPL Small-Body Database Browser: 132 Aethra" (2000-06-10 last obs). Retrieved 12 May 2016.
- ^ a b c Fienga, A.; Avdellidou, C.; Hanuš, J. (February 2020). "Asteroid masses obtained with INPOP planetary ephemerides". Monthly Notices of the Royal Astronomical Society. 492 (1). doi:10.1093/mnras/stz3407.
- ^ Herget, Paul (1938). "The orbit and perturbations of (132) Aethra". Astronomical Journal. 47 (1081): 17–23. Bibcode:1938AJ.....47...17H. doi:10.1086/105455.
- ^ Fred William Price (2000). The Planet Observer's Handbook. Cambridge University Press. p. 192. ISBN 978-0-521-78981-3.
External links edit
- 132 Aethra at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
- 132 Aethra at the JPL Small-Body Database
