[en] | 129 Antigone

129 Antigone is a large main-belt asteroid. Radar observations indicate that it is composed of almost pure nickeliron. It and other similar asteroids probably originate from the core of a shattered Vesta-like planetesimal which had a differentiated interior. It was discovered by German-American astronomer C. H. F. Peters on February 5, 1873, and named after Antigone, the Theban princess in Greek mythology.

129 Antigone
Discovery
Discovered byChristian Heinrich Friedrich Peters
Discovery date5 February 1873
Designations
(129) Antigone
Pronunciation/ænˈtɪɡən/[1]
Named after
Antigone
A873 CA; 1878 CA;
1907 BA
Main belt
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc112.47 yr (41080 d)
Aphelion3.4773 AU (520.20 Gm)
Perihelion2.26344 AU (338.606 Gm)
2.87038 AU (429.403 Gm)
Eccentricity0.21145
4.86 yr (1776.3 d)
17.39 km/s
97.3536°
0° 12m 9.619s / day
Inclination12.262°
135.703°
111.076°
Earth MOID1.2837 AU (192.04 Gm)
Jupiter MOID1.7487 AU (261.60 Gm)
TJupiter3.232
Physical characteristics
Dimensions113[2]
119.44 ± 3.91 km[3]
Mass(2.65 ± 0.89) × 1018 kg[3]
Mean density
2.96 ± 1.04 g/cm3[3]
Equatorial surface gravity
0.0349 m/s2
Equatorial escape velocity
0.0661 km/s
4.9572 h (0.20655 d)[2][4]
0.164
Temperature~164 K
M
9.71 (brightest?)
7.07

In 1979 a possible satellite of Antigone was suggested based on lightcurve data.[5] A model constructed from these shows Antigone itself to be quite regularly shaped. In 1990, the asteroid was observed from the Collurania-Teramo Observatory, allowing a composite light curve to be produced that showed a rotation period of 4.9572 ± 0.0001 hours and a brightness variation of 0.34 ± 0.01 in magnitude. The ratio of the lengths of the major to minor axes for this asteroid were found to be 1.45 ±0.02.[4]

10μ radiometric data collected from Kitt Peak in 1975 gave a diameter estimate of 114 km.[6] Since 1985, a total of three stellar occultations by Antigone have been observed. A favorable occultation of a star on April 11, 1985, was observed from sites near Pueblo, Colorado, allowing a diameter estimate of 113.0 ± 4.2 km to be calculated.[7]

References

  1. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  2. ^ a b c Yeomans, Donald K., “129 Antigone”, JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 12 May 2016.
  3. ^ a b c Carry, B. (December 2012), “Density of asteroids”, Planetary and Space Science, vol. 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS…73…98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
  4. ^ a b Dotto, E.; et al. (June 1992), “M-type asteroids – Rotational properties of 16 objects”, Astronomy and Astrophysics Supplement Series, vol. 95, no. 2, pp. 195–211, Bibcode:1992A&AS…95..195D.
  5. ^ Johnston, Wm. Robert (17 February 2013), “Other Reports of Asteroid/TNO Companions”, Johnston’s Archive, retrieved 29 March 2013.
  6. ^ Morrison, D.; Chapman, C. R. (March 1976), “Radiometric diameters for an additional 22 asteroids”, Astrophysical Journal, vol. 204, pp. 934–939, Bibcode:2008mgm..conf.2594S, doi:10.1142/9789812834300_0469.
  7. ^ Wasserman, L. H.; et al. (June 1986), “The Occultation of AG + 20° 1138 by 129 Antigone on 11 April 1985”, Bulletin of the American Astronomical Society, vol. 18, p. 797, arXiv:1203.4336, Bibcode:2012P&SS…73…98C, doi:10.1016/j.pss.2012.03.009.

Source: en.wikipedia.org