| Minorplanet: | yes |
| Background: |
|
| 129 Antigone | |
| Discovered: | 5 February 1873 |
| Mpc Name: | (129) Antigone |
| Alt Names: | A873 CA; 1878 CA; 1907 BA |
| Pronounced: | [1] |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Semimajor: | 2.87038AU |
| Perihelion: | 2.26344AU |
| Aphelion: | 3.4773abbr=onNaNabbr=on |
| Eccentricity: | 0.21145 |
| Period: | 4.86 yr (1776.3 d) |
| Inclination: | 12.262° |
| Asc Node: | 135.703° |
| Arg Peri: | 111.076° |
| Avg Speed: | 17.39 km/s |
| Dimensions: | 113 119.44 ± 3.91 km |
| Density: | 2.96 ± 1.04 g/cm3 |
| Surface Grav: | 0.0349 m/s2 |
| Escape Velocity: | 0.0661 km/s |
| Rotation: | 4.9572abbr=onNaNabbr=on |
| Magnitude: | 9.71 (brightest?) |
| Abs Magnitude: | 7.07 |
| Albedo: | 0.164 |
| Mean Motion: | / day |
| Observation Arc: | 112.47 yr (41080 d) |
| Uncertainty: | 0 |
| Moid: | 1.2837AU |
| Jupiter Moid: | 1.7487AU |
| Tisserand: | 3.232 |
129 Antigone is a large main-belt asteroid. Radar observations indicate that it is composed of almost pure nickel-iron. 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.
In 1979 a possible satellite of Antigone was suggested based on lightcurve data. 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.
10μ radiometric data collected from Kitt Peak in 1975 gave a diameter estimate of 114 km. 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.