Asteroids with Satellites Database--Johnston's Archive

(469705) 2005 EF298

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, Cubewano


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 44.0581 AU
orbital period P: 292.441 yr
(= 106816.1 d)
eccentricity e: 0.091812
perihelion distance q: 40.013 AU
aphelion distance Q: 48.1031 AU
inclination i: 2.868°
argument of perihelion ω: 77.9656°
ascending node Ω: 118.059°
mean anomaly M: 338.3824°
perihelion passage TP: 2036 Nov 17.2
Epoch: 2019 Apr 27
data arc: 2005-2015 (129 obs.)
Earth MOID: 39.0136 AU
Jupiter Tisserand invariant TJ: 5.906
Neptune Tisserand invariant TN:3.090 [*D]


orbital data, secondary:
semimajor axis as: 7670 ± 140 km [G19b]
separation/primary radius as/rp:111 [*D]
separation/Hill radius as/rH:0.018 [*D]
orbital period Ps: 128.107 ± 0.027 d [G19b]
eccentricity es: 0.694 ± 0.013 [G19b]
inclination is:33.33° ± 0.41° [G19b]
ascending node Ωs:4.13° ± 0.32° [G19b]
argument of pericenter ωs:183.57° ± 0.76° [G19b]
mean anomaly M:136.08° ± 0.88° [G19b]
Epoch:2011 Feb 07.5
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 5.9 [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: 2.18x1018 ± 1.2x1017 kg [G19b]
density ρ: 1.1 ± 0.61 g/cm3[K17b]
Hill radius rH: 430000 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: ?

-- (469705) 2005 EF298 --discovery and notes:

Primary discovered 2005 Mar 11 from Kitt Peak Observatory, Arizona, USA by M. W. Buie. Permanent number assigned 2016 Aug 18.

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:


© 2011-2015, 2019 by Wm. Robert Johnston.
Last modified 27 May 2019.
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