90482 Orcus Facts for Kids

Quick facts for kids
90482 Orcus
Discovery

Discovered by	M. Brown, C. Trujillo, D. Rabinowitz
Discovery date	February 17, 2004
Designations
Alternative names	2004 DW
Minor planet category	Plutino
Orbital characteristics
Epoch November 30, 2008 (JD 2 454 800)
Aphelion	7 188.17 Gm (48.05 AU)
Perihelion	4 535.80 Gm (30.32 AU)
Semi-major axis	5 862.44 Gm (39.188 AU)
Eccentricity	0.226 18
Orbital period	89 606 d (245.33 yr)
Average orbital speed	4.68 km/s
Mean anomaly	164.68°
Inclination	20.593°
Longitude of ascending node	268.722°
Argument of perihelion	72.474°
Known satellites	1 (92-432 km)
Physical characteristics
Dimensions	946.3 ^+74.1_−72.3 km (diameter)
Mass	~7.5×10²⁰ kg
Mean density	~1.5 g/cm³ (assumed)
Surface gravity	~0.2 m/s²
Escape velocity	~0.44 km/s
Rotation period	13.19h
Albedo	19.75 ^+3.40_−2.76 %
Temperature	~45 K
Spectral type	B-V=0.68; V-R=0.37
Apparent magnitude	19.1 (opposition)
Absolute magnitude (H)	2.3

90482 Orcus, originally known by the provisional designation 2004 DW, is a Kuiper belt object (KBO). It is also a dwarf planet. It was found by Michael Brown, Chad Trujillo and David Rabinowitz on February 17, 2004. It was also seen in pictures from November 8, 1951. Like Pluto it is in orbital resonance with Neptune but it stays on the opposite side of the Sun from Pluto.

Moon

A moon of Orcus was found on 22 February 2007.

The satellite was found at 0.25 arcsec from Orcus with magnitude difference of 2.7. Assuming an albedo similar to that of the primary, the magnitude suggests a diameter of about 220 km. It is thought to be a smaller KBO that was captured.

The Solar System

Sun • Heliosphere	Planets ☾ = moon(s) ∅ = rings		Mercury	Venus	Earth ☾	Mars ☾

			Jupiter ☾ ∅	Saturn ☾ ∅	Uranus ☾ ∅	Neptune ☾ ∅

	Dwarf planets		Ceres	Pluto ☾	Haumea ☾	Makemake

			Eris ☾

	Small Solar System bodies	Asteroids (minor planets)	Groups and families: Vulcanoids · Near-Earth asteroids · Asteroid belt Jupiter Trojans · Centaurs · Neptune Trojans · Asteroid moons · Meteoroids · Pallas · Juno · Vesta · Hygiea · Interamnia · Europa
		Asteroids (minor planets)	See also the list of asteroids.

		Trans- Neptunians	Kuiper belt – Plutinos: Orcus · Ixion – Cubewanos: Varuna · Quaoar · Huya
		Trans- Neptunians	Scattered disc: Sedna

		Comets	Periodic comets and non-periodic comets Damocloids · Oort cloud
See also the list of solar system objects

Images for kids

Discovery image of Orcus taken in 2004
Orcus compared to Earth and the Moon
Long-exposure photograph of Orcus at visual magnitude 19.2
Orcus and Vanth imaged by Hubble in 2006

90482 Orcus facts for kids

Moon

Images for kids

See also