Neptune VIII
| Proteus Statistics | |
|---|---|
| Discovered by | Stephen Synnott |
| Date of discovery | 1989 |
| Mass (kg) | ? |
| Equatorial radius (km) | 200 |
| Equatorial radius (Earth = 1) | 3.1358e-02 |
| Mean density (gm/cm^3) | ? |
| Mean distance from Neptune (km) | 117,600 |
| Rotational period (days) | ? |
| Orbital period (days) | 1.122315 |
| Mean orbital velocity (km/sec) | 7.63 |
| Orbital eccentricity | 0.0004 |
| Orbital inclination (degrees) | 0.04 |
| Visual geometric albedo | 0.06 |
| Magnitude (Vo) | 20.3 |