Asteroids with Satellites Database--Johnston's Archive

(136199) Eris and Dysnomia

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, scattered disk


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 67.8363 AU
orbital period P: 558.730 yr
(= 204076.0 d)
eccentricity e: 0.439647
perihelion distance q: 38.0123 AU
aphelion distance Q: 97.6603 AU
inclination i: 43.99099°
argument of perihelion ω: 150.8942°
ascending node Ω: 35.97898°
mean anomaly M: 203.908°
perihelion passage TP: 2256 Aug 26
Epoch: 2014 May 23
data arc: 1954-2013 (610 obs.)
Earth MOID: 37.0703 AU
Jupiter Tisserand invariant TJ: 4.743
Neptune Tisserand invariant TN:2.38 [*D]


orbital data, secondary:
semimajor axis as: 37580 ± 260 km [G11a]
separation/primary radius as/rp:32 [*D]
separation/Hill radius as/rH:0.0047 [*D]
orbital period Ps: 15.79 ± 0.0014 d [G11a]
eccentricity es: 0.017 ± 0.007 [G11a]
inclination is:61.3° ± 0.7° [B07c]
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: -1.2 [MPC]
-1.12 ± 0.03 [S12a]
slope parameter G: (0.15) [*A]
effective diameter dE: 2380 km [*D]
geometric albedo: 0.96 ± 0.09/0.04 [S11a]
color index U-B: ?
color index B-V: 0.823 [C06c]
color index V-R:0.391 ± 0.023 [C06c]
color index B-R:1.214 [C06c]
color index V-I:0.777 ± 0.013 [C06c]
color index R-J:0.56 [B05c]
color index J-H:-0.29 [B05c]
taxonomic type: BB (G-mode) [P10a]
mass m: 1.66x1022 ± 2x1020 kg [B07c]
density ρ: 2.52 ± 0.05/0.05 g/cm3[S11a]
Hill radius rH: 8000000 km [*D]

other data, primary:
diameter dp: 2326 ± 12 km [S11a]
rotation period RPp: 25.92 ± 0.48 h [R08a]
amplitude in mag., rotational ΔM: 0.1 [R08a]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 514 ± 221 km [S12a]
diameter ratio ds/dp: 0.046 [G11a]
component mag. difference ΔM: 4.43 ± 0.05 [I8610]
geometric albedo :?[]
rotation period RPs: ?

-- (136199) Eris and Dysnomia --discovery and notes:

Primary discovered 2003 Oct 21 from Palomar Observatory, California, USA by M. E. Brown, C. A. Trujillo, and D. L. Rabinowitz. Alternate designation(s): 2003 UB313 . Linked to prediscovery observations from 1954 Sep 03. Permanent number assigned 2006 Sep 07.

Named 2006 Sep 14 for the mythological Greek goddess of discord [MPC57800].

Companion discovered 2005 Sep 10 by M. E. Brown, et al. using adaptive optics telescope observations from W. M. Keck II Telescope, Mauna Kea, Hawaii, USA. Announced 2005 Oct 02 [B05d]. Provisional designation S/2005 (2003 UB313) 1. Permanent designation I Dysnomia, assigned 2006 Sep 14; named for the Greek mythological spirit of lawlessness [G06d].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2005-2008, 2014 by Wm. Robert Johnston.
Last modified 20 September 2014.
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