Asteroids with Satellites Database--Johnston's Archive

2005 EF298

compiled by Wm. Robert Johnston
last updated 31 January 2015

--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, Cubewano


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 44.26224779 AU
orbital period P: 294.4817599 yr
(= 107559.4628 d)
eccentricity e: 0.093682629
perihelion distance q: 40.11564404 AU
aphelion distance Q: 48.40885154 AU
inclination i: 2.863785393°
argument of perihelion ω: 74.15028819°
ascending node Ω: 117.96009°
mean anomaly M: 335.7177367°
perihelion passage TP: 2034 Apr 02
Epoch: 2014 May 23
data arc: 2005-2013 (61 obs.)
Earth MOID: 39.1174 AU
Jupiter Tisserand invariant TJ: 5.918
Neptune Tisserand invariant TN:3.092 [*D]


orbital data, secondary:
semimajor axis as: 7700 ± 100 km [G14a]
separation/primary radius as/rp:112 [*D]
separation/Hill radius as/rH:0.019 [*D]
orbital period Ps: 128.11 ± 0.03 d [G14a]
eccentricity es: 0.69 ± 0.01 [G14a]
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 6.1 [MPC]
6.4 ± 0.5 [V12a]
slope parameter G: (0.15) [*A]
effective diameter dE: 174 ± 27/32 km [V12a]
geometric albedo: 0.16 ± 0.13/0.07 [V12a]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: 2.2x1018 ± 1x1017 kg [G14a]
density ρ: (1 g/cm3) [*A]
Hill radius rH: 420000 km [*E]

other data, primary:
diameter dp: 138 km [*E]
rotation period RPp: 9.65 h [B13a]
amplitude in mag., rotational ΔM: 0.31 ± 0.04 [B13a]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 105 km [*E]
diameter ratio ds/dp: 0.762 [G12b]
component mag. difference ΔM: 0.59 [G12b]
rotation period RPs: ?

-- 2005 EF298 --discovery and notes:

Primary discovered 2005 Mar 11 from Kitt Peak Observatory, Arizona, USA by M. W. Buie.

Companion discovered 2009 Jan 21 using Hubble Space Telescope observations from Hubble Space Telescope. Announced 2011.

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2011-2014, 2015 by Wm. Robert Johnston.
Last modified 31 January 2015.
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