Erriapus
Discovery images of Erriapus taken by the CFHT in September 2000 | |
| Discovery | |
|---|---|
| Discovered by | John J. Kavelaars et al. |
| Discovery date | 2000 |
| Designations | |
Designation | Saturn XXVIII |
| Pronunciation | /ɛriˈæpəs/ |
Named after | Erriap(p)us |
| S/2000 S 10 | |
| Orbital characteristics | |
| Epoch 2000 January 1.5 | |
| 17 507 200 km | |
| Eccentricity | 0.462 |
| 871.1 d (2.38 yr) | |
| Inclination | 38.7 |
| Satellite of | Saturn |
| Group | Gallic group |
| Physical characteristics | |
| Dimensions | 16.30 × 10 × 6.34 km (modeled) |
| 10+50% −30% km | |
| 28.15±0.25 h | |
| Albedo | 0.06 (assumed) |
Spectral type | light red B−V=0.83, R−V=0.49 |
| 23.0 | |
| 13.7 | |
Erriapus /ɛriˈæpəs/, or Saturn XXVIII (28), is a prograde irregular satellite of Saturn. It was discovered by Brett Gladman, John J. Kavelaars and colleagues in 2000, and given the temporary designation S/2000 S 10. It was named Erriapo in August 2003 after Erriapus (also rendered Erriappus), a giant in Gaulish mythology; the name was changed from dative Erriapo to nominative Erriapus per IAU conventions in late 2007.
Erriapus is about 10 kilometres in diameter, and orbits Saturn at an average distance of 17.5 Gm in 871 days.
As a member of the Gallic group of irregular satellites, which share similar orbital characteristics and a light-red colour, Erriapus is hypothesized to have its origin in the break-up of a common progenitor of the group, or to be a fragment of its largest member, Albiorix. It has a rotation period of 28.15±0.25 h, and is thought to rotate on its side, giving it similar seasons to those of Uranus. With a fairly elongated shape, it is a candidate for a contact binary or binary moon.