| Diameter: 1,600km Distance from Sun: 47.92 AU (150,000,000 km) Elliptical orbit of the Sun: 248yrs Satellite: Moons 1: Vanth |
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| Discovered By: | M. Brown, C.Trujillo, D. Rabinowitz | |
| Date of Discovery: | 17th February 2004 | |
| Average Distance from the Sun | ||
| Orbits Earth: | 245.18yr (89,522 d) | |
| Epoch: | 23rd July 2010 (JD 2455400.5) | |
| Perihelion (closest) |
30.27 AU (4.52833 Gm) |
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| Aphelion (farthest) | 48.07.313 AU (7.19117 Tm ) | |
| Argument of Perihelion | 73.01° | |
| Semi-major Axis | 39.173 AU (5.86018 Tm) | |
| Eccentricity | 0.22718 | |
| Average Orbital Velocity | ||
| Mean Anomally | 166.38° | |
| Mean Density | 2.3 ± 0.8 g/cm3 | |
| Orbital Period | 245.18 yr (89,552 d) | |
| Inclination (tilt) | 20.573° | |
| Longitude of Ascending Node | 268.606° | |
| Mean Radius | ||
| Mass | 6.41 ± 0.19×1020 kg (system) | |
| Equatorial Surface Gravity | ~0.27 m/s2 | |
| Rotation Period | 13.188 hr | |
| Albedo | 0.28 ± 0.04[6] 0.27+0.07 -0.05 19.75 +3.40 -2.76% |
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| Apparent Magnitude | 19.1 (opposition) | |
| Absolute Magnitude (H) | 2.3 (2.27+/-0.05 Moon: 4.88+/-0.05 |
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| Angular Diameter | ||
| Temperature (Aphelion) (Perihelion) |
~44k | |
| Spectra Data Atmosphere | (neutral) B-V=0.93; V-R=0.64 | |
| Composition: | Rock and Ice | |
| Category: | Orcus is a plutino, locked in a 2:3 resonance with Neptune, making two revolutions around the Sun, while Neptune makes three. with its large moon Vanth that recalls Pluto's large moon Charon, Orcus has been seen as the anti-Pluto. This was a major consideration in selecting its name, as the deity Orcus was the Etruscan equivalent of the Roman Pluto, and later became an alternate name for Pluto | |
| Notes: | Grey in color and water rich. The ice is predominantly in crystalline form, which may be related to past cryovolcanic activity. Other compounds like methane or ammonia may also be present.https://ssd.jpl.nasa.gov/sbdb.cgi#top |
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