Francisco (moon)
Francisco imaged by the Very Large Telescope on 3 September 2002 | |
| Discovery | |
|---|---|
| Discovered by | |
| Discovery site | Cerro Tololo Obs. |
| Discovery date | 13 August 2001 |
| Designations | |
Designation | Uranus XXII |
| Pronunciation | /frænˈsɪskoʊ/ |
Named after | Francisco (The Tempest character) |
| S/2001 U 3 | |
| Orbital characteristics | |
| Epoch 1 January 2020 (JD 2458849.5) | |
| Satellite of | Uranus |
| Proper orbital elements | |
Proper semi-major axis | 4,275,700 km (0.028581 AU) |
Proper eccentricity | 0.144 |
Proper inclination | 146.8° (to ecliptic) |
Proper orbital period | 0.73 years (267 d) |
Precession of perihelion | 103.904434 arcsec / yr |
Precession of the ascending node | 89.8814065 arcsec / yr |
| Physical characteristics | |
| 11–17 km 22 km | |
| 25.0 (average) | |
| 12.9 | |
Francisco, also known as Uranus XXII and previously as S/2001 U 3, is the innermost known irregular satellite of Uranus, orbiting in a retrograde direction. It was discovered on 13 August 2001 by John J. Kavelaars, Matthew J. Holman, Dan Milisavljevic, and Tommy Grav using the 4.0-meter Víctor M. Blanco Telescope at Cerro Tololo Observatory, Chile. It was named after Francisco, a lord in William Shakespeare's play The Tempest. Francisco orbits Uranus at an average distance of 4.3 million km (2.7 million mi) and takes about 267 Earth days (0.73 Earth years) to complete one orbit. Francisco is estimated to be up to 22 km (14 mi) in diameter, though many of its physical properties are unknown.