Asteroids with Satellites Database--Johnston's Archive

(90482) Orcus and Vanth

compiled by Wm. Robert Johnston
last updated 27 May 2019

--Orbital and physical data--

(See this page for definitions of quantities; source codes in brackets, see this link for full references; *A, *D, and *E indicate assumed, derived, and estimated values, respectively.)

dynamical type, primary: TNO, plutino


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 39.4597 AU
orbital period P: 247.873825088923 yr
(= 90537.8 d)
eccentricity e: 0.21843
perihelion distance q: 30.8406 AU
aphelion distance Q: 48.0789 AU
inclination i: 20.552009°
argument of perihelion ω: 73.3952°
ascending node Ω: 268.48161°
mean anomaly M: 172.5691°
perihelion passage TP: 1896 Feb 10.94
Epoch: 2014 Dec 09
data arc: 1951-2014 (430 obs.)
Earth MOID: 29.8932 AU
Jupiter Tisserand invariant TJ: 5.164
Neptune Tisserand invariant TN:2.856 [*D]


orbital data, secondary:
semimajor axis as: 8999.8 ± 9.1 km [G19b]
separation/primary radius as/rp:19.8 [*D]
separation/Hill radius as/rH:0.0041 [*D]
orbital period Ps: 9.539154 ± 0.00002 d [G19b]
eccentricity es: 0.00091 ± 0.00053 [G19b]
inclination is:105.03° ± 0.18° [G19b]
ascending node Ωs:53.49° ± 0.33° [G19b]
argument of pericenter ωs:328° ± 51° [G19b]
mean anomaly M:188.52° ± 0.39° [G19b]
Epoch:2006 Sep 21.5
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 2.2 [MPC]
2.31 ± 0.03 [F13a]
slope parameter G: 0.28 [B09b]
effective diameter dE: 1012 ± 45 km [*D]
geometric albedo: 0.231 ± 0.018/0.011 [F13a]
color index U-B: ?
color index B-V: 0.68 [D05b]
color index V-R:0.37 ± 0.04 [D05b]
color index B-R:1.05 [D05b]
color index V-I:0.74 ± 0.04 [D05b]
color index R-J:0.82 ± 0.05 [P10a]
color index V-J:1.08 ± 0.04 [D05b]
color index J-H:0.19 ± 0.09 [P10a]
color index V-H:1.21 ± 0.05 [D05b]
taxonomic type: BB (G-mode) [P10a]
mass m: 6.35x1020 ± 1.9x1018 kg [G19b]
density ρ: 1.4 ± 0.2 g/cm3[B18f]
Hill radius rH: 2200000 km [*D]

other data, primary:
diameter dp: 910 ± 45 km [B18f]
rotation period RPp: 13.188 ± 0 h [R07a]
amplitude in mag., rotational ΔM: 0.04 ± 0.01 [T10a]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 443 ± 10 km [S19b]
diameter ratio ds/dp: 0.487 ± 0.026 [*D]
component mag. difference ΔM: 2.61 ± 0.07 [B09b]
rotation period RPs: 229 h [R14a]

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

Primary discovered 2004 Feb 17 from Palomar Observatory, California, USA by M. E. Brown, C. A. Trujillo, and D. L. Rabinowitz. Alternate designation(s): 2004 DW . Linked to prediscovery observations from 1951 Nov 08. Permanent number assigned 2004 Aug 30.

Named 2004 Nov 22 for the mythological Etruscan daimon [MPC053177].

Companion discovered 2005 Nov 13 by M. E. Brown and T.-A. Suer using Hubble Space Telescope observations from Hubble Space Telescope. Announced 2007 Feb 22 [B07d]. Permanent designation I Vanth, assigned 2010 Mar 30; named for the Etruscan mythological creature [MPC69496].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2007-2014, 2019 by Wm. Robert Johnston.
Last modified 27 May 2019.
Return to Home. Return to Astronomy and Space. Return to Asteroids with Satellites.