Asteroids with Satellites Database--Johnston's Archive

(90482) Orcus and Vanth

compiled by Wm. Robert Johnston
last updated 20 September 2014

--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: 39.4386 AU
orbital period P: 247.680 yr
(= 90465.0 d)
eccentricity e: 0.219161
perihelion distance q: 30.7952 AU
aphelion distance Q: 48.0820 AU
inclination i: 20.547804°
argument of perihelion ω: 73.5556°
ascending node Ω: 268.45133°
mean anomaly M: 171.5620°
perihelion passage TP: 1896 May 08.9
Epoch: 2014 May 23
data arc: 1951-2014 (433 obs.)
Earth MOID: 29.8463 AU
Jupiter Tisserand invariant TJ: 5.162
Neptune Tisserand invariant TN:2.86 [*D]


orbital data, secondary:
semimajor axis as: 9006 ± 16 km [G11a]
separation/primary radius as/rp:20 [*D]
separation/Hill radius as/rH:0.0041 [*D]
orbital period Ps: 9.539 ± 0.0001 d [G11a]
eccentricity es: 0.001 ± 0.001 [G11a]
inclination is:90.2° ± 0.6° [B09b]
ascending node Ωs:50° ± 0.6° [B09b]
mean anomaly M:143.1° ± 0.02° [B09b]
Epoch:2007 Dec 04.78
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: 958.4 ± 22.9/22.9 km [F13a]
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: 6.36x1020 ± 3.3x1018 kg [G11a]
density ρ: 1.53 ± 0.15/0.13 g/cm3[F13a]
Hill radius rH: 2200000 km [*D]

other data, primary:
diameter dp: 917 ± 25 km [F13a]
rotation period RPp: 13.18841 ± 0.00111 h [R07a]
amplitude in mag., rotational ΔM: 0.04 ± 0.01 [T10a]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 276 ± 17 km [F13a]
diameter ratio ds/dp: 0.31 [B10b]
component mag. difference ΔM: 2.61 ± 0.07 [B09b]
rotation period RPs: ?

-- (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 [MPC53177].

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:


© 2007-2010, 2014 by Wm. Robert Johnston.
Last modified 20 September 2014.
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