Properties
Magnitude
14.1
Angular Size
0.1 arcmin
Type: Moon
Distance: 0.004 AU
Orbital Period: 13.5 days
Diameter: 1,523 km
Features: Craters, chasma, dark patches
Second largest moon of Uranus; named after the king of fairies in A Midsummer Night's Dream. Dark, heavily cratered surface. Requires 8-10 inch telescope under dark skies.
Position & Identifiers
RA
03h 48m 15.1s
Dec
+19° 49' 48.7"
Constellation
Taurus
Catalog
Oberon
Physical Properties
Diameter
1,523 km
(0.12× Earth)
Mass
3.01e21 kg
Albedo
0.23
(23% reflected)
Temperature
-213°C to -198°C
Rotation
13.5 days
Surface
Craters, chasma, dark patches
Angular Size
0.1″ (current)
Orbital Properties
Semi-major Axis
0.0039 AU
(583,432 km)
Eccentricity
0.0014
Inclination
0.06°
Orbital Period
13.5 days
Distance
20.061 AU
(2.78 light-hours)
Elongation
53.3°
Moderate
Observing Tips
Best Months
September
, October
, November
Visibility
Telescope
Where to Look
Near Uranus
Notes
Second largest moon of Uranus; named after the king of fairies in A Midsummer Night's Dream. Dark, heavily cratered surface. Requires 8-10 inch telescope under dark skies.
Parent Body
Discovery
Discovered by
William Herschel
Date
1787-01-11
Current Ephemeris
20.061
AU from Earth
3.00B
km
0.1″
Angular Size
53°
Elongation
Visibility
Set a location in User Settings to see visibility data.
Community Photos (1)
Credit: Kevin M. Gill. License: CC BY 2.0. (Wikimedia Commons)
Skybred Feb 28, 2026