(90482) Orcus

compiled by Wm. Robert Johnston
last updated 4 March 2007

Orbital elements and other data (Assumed or derived values in parenthesis, my estimates in italics and parenthesis. Source identifications in brackets, see this link for sources):

orbital data, primary (osculating elements) [JPL]:
semimajor axis a: 39.301 AU
orbital period P: 246.38 y (=89,991.0 d)
eccentricity e: 0.22248
perihelion distance q: 30.557 AU
aphelion distance Q: 48.044 AU
inclination i: 20.59398°
argument of perihelion omega: 72.41°
ascending node OMEGA: 268.7244°
mean anomaly M: 162.48°
perihelion passage TP: 1896-01-26.7
Epoch: 10 APR 2007
data arc: 1951-2004 (112 obs.)

orbital data, secondary:
semimajor axis a: (8,700 km separation) [I8812]
semimajor axis/primary radius a/Rp: (19?)
orbital period P: (~11 d?)
eccentricity e: ?

other data, primary:
diameter: 946 +74/-72 km [S07a] (combined)
(909 km)
absolute magnitude H: 2.27±0.03 [D05b]
rotation period: (13.18841±0.00111 h) [R07a]
amplitude delta M: 0.04 ± 0.02 [O05a]
0.18 ± 0.08 [R07a]
color index B-V: 0.68±0.04 [D05b]
color index V-R: 0.37±0.04 [D05b]
color index V-I: 0.74±0.04 [D05b]
color index V-J: 1.08±0.04 [D05b]
color index V-H: 1.21±0.05 [D05b]
slope parameter G: (0.15) assumed
geometric albedo: 0.197 +0.034/-0.028 [S07a]
mass: ?
density: ?
type: ?

other data, secondary:
diameter: (262 ± 170 km)
diameter ratio Ds/Dp: (0.29 ± 0.17)
component magnitude difference: 2.7±1.0 [I8812]
rotation period: ?

--(90482) Orcus--discovery and notes:

Primary discovered 17 February 2004 by M. Brown, C. Trujillo, and D. Rabinowitz from Palomar Observatory, California, USA. Linked to prediscovery observations from 8 November 1951. Alternate designation 2004 DW.

Companion discovered by M. E. Brown and T.-A. Suer using Hubble Space Telescope observations from 13 November 2005; reported 22 February 2007.

See more information and links at Asteroid/Comet Connection Catchall Catalog page

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2007 by Wm. Robert Johnston.
Last modified 4 March 2007.
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