[en] | 132 Aethra

132 Aethra is a metallic asteroid and Mars-crosser on an eccentric orbit from the asteroid belt. It measures approximately 40 kilometers in diameter.

132 Aethra
Lightcurve-based 3D-model of Aethra
Discovery
Discovered byJames C. Watson
Discovery date13 June 1873
Designations
(132) Aethra
Pronunciation/ˈθrə/[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 arc142.50 yr (52049 d)
Aphelion3.6250 AU (542.29 Gm)
Perihelion1.5895 AU (237.79 Gm)
2.6073 AU (390.05 Gm)
Eccentricity0.39036
4.21 yr (1537.7 d)
17.72 km/s
38.271°
0° 14m 2.796s / day
Inclination24.997°
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]

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

  1. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  2. ^ a b c d e “JPL Small-Body Database Browser: 132 Aethra” (2000-06-10 last obs). Retrieved 12 May 2016.
  3. ^ 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.
  4. ^ Herget, Paul (1938). “The orbit and perturbations of (132) Aethra”. Astronomical Journal. 47 (1081): 17–23. Bibcode:1938AJ…..47…17H. doi:10.1086/105455.
  5. ^ Fred William Price (2000). The Planet Observer’s Handbook. Cambridge University Press. p. 192. ISBN 978-0-521-78981-3.

Source: en.wikipedia.org