13 Egeria
A deconvolved image of 13 Egeria by VLT/SPHERE | |
| Discovery | |
|---|---|
| Discovered by | Annibale de Gasparis |
| Discovery site | Naples Obs. |
| Discovery date | 2 November 1850 |
| Designations | |
| (13) Egeria | |
| Pronunciation | /ɪˈdʒɪəriə/ |
Named after | Egeria |
| 1850 VA | |
| Main belt | |
| Adjectives | Egerian |
| Symbol | (historical) (historical, variant) |
| Orbital characteristics | |
| Epoch 17.0 October 2024 (JD 2460600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 63566 days (174.03 yr) |
| Aphelion | 2.79788 AU |
| Perihelion | 2.35759 AU |
| 2.57774 AU | |
| Eccentricity | 0.085403 |
| 4.14 yr (1511.7 d) | |
Average orbital speed | 18.56 km/s |
| 305.547° | |
| 0° 14m 17.34s / day | |
| Inclination | 16.532° |
| 43.208° | |
| 79.222° | |
| Earth MOID | 1.43636 AU |
| Jupiter MOID | 2.35842 AU |
| TJupiter | 3.363 |
| Physical characteristics | |
| Dimensions | 214.8 km × 192 km 238 km × 199 km × 182 km (± 12 km × 11 km × 10 km) |
| 202±3 km 207.6 ± 8.3 km (IRAS) | |
| Flattening | 0.24 |
| Mass | (9.2±2.1)×1018 kg (15.9±4.4)×1018 kg |
Mean density | 2.13±0.49 g/cm3 3.4±1.0 g/cm3 |
Equatorial surface gravity | ≈0.0580 m/s2 |
Equatorial escape velocity | ≈0.1098 km/s |
| 7.045 h 7.046664±0.000003 h | |
| 59° | |
Pole ecliptic longitude | 38°±5° |
Pole ecliptic latitude | 31°±5° |
| 0.087 0.049 ± 0.028 0.085 ± 0.007 | |
| Temperature | ~174 K |
| G-type asteroid | |
| 9.71 to 12.46 | |
| 6.91 6.74 | |
13 Egeria is a large main-belt G-type asteroid. It was discovered by Annibale de Gasparis on 2 November 1850. Egeria was named by Urbain Le Verrier, whose computations led to the discovery of Neptune, after the mythological nymph Egeria of Aricia, Italy, the wife of Numa Pompilius, second king of Rome.