38 Leda
Leda (minor planet designation: 38 Leda) is a large, dark main-belt asteroid that was discovered by French astronomer J. Chacornac on January 12, 1856, and named after Leda, the mother of Helen of Troy in Greek mythology. In the Tholen classification system, it is categorized as a carbonaceous C-type asteroid, while the Bus asteroid taxonomy system lists it as a Cgh asteroid. The spectra of the asteroid displays evidence of aqueous alteration.
A three-dimensional model of 38 Leda based on its light curve | |
| Discovery | |
|---|---|
| Discovered by | J. Chacornac |
| Discovery date | January 12, 1856 |
| Designations | |
Designation | (38) Leda |
| Pronunciation | /ˈliːdə/ |
Named after | Leda |
Alternative names | A904 SF; 1949 QO2 |
Minor planet category | Main belt |
| Adjectives | Ledean /lɪˈdiːən/ (Latin Lēdæ-us) |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion | 472.587 Gm (3.159 AU) |
| Perihelion | 348.232 Gm (2.328 AU) |
Semi-major axis | 410.409 Gm (2.743 AU) |
| Eccentricity | 0.152 |
Orbital period (sidereal) | 1659.725 d (4.54 a) |
Average orbital speed | 17.88 km/s |
Mean anomaly | 107.567° |
| Inclination | 6.955° |
Longitude of ascending node | 295.890° |
| 168.804° | |
| Physical characteristics | |
| Dimensions | 92.255 ± 0.490 km |
| Mass | (7.16 ± 3.38/2.24)×1017 kg |
Mean density | 1.743 ± 0.822/0.544 g/cm3 |
Surface gravity | 0.0225 m/s² |
| 0.0455 km/s | |
Synodic rotation period | 0.5350 d (12.84 h) |
| Albedo | 0.055 |
| Temperature | ~170 K |
Spectral type | C |
| 8.32 | |
Leda has been studied by radar. During 2002, 38 Leda was observed by radar from the Arecibo Observatory. The return signal matched an effective diameter of 116 ± 13 km. This is consistent with some asteroid dimensions computed through other means. Based upon a light curve that was generated from photometric observations of this asteroid at Pulkovo Observatory, it has a rotation period of 12.834 ± 0.001 hours and varies in brightness by 0.15 ± 0.01 in magnitude.