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 | |
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] | |
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.
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): 589–602. 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
- 132 Aethra at the JPL Small-Body Database
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction