Asteroids with Satellites Database--Johnston's Archive

2001 XR254

compiled by Wm. Robert Johnston
last updated 23 June 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: 43.21484292 AU
orbital period P: 284.0910882 yr
(= 103764.27 d)
eccentricity e: 0.028758088
perihelion distance q: 41.97206668 AU
aphelion distance Q: 44.45761915 AU
inclination i: 1.234114469°
argument of perihelion ω: 68.7945569°
ascending node Ω: 179.6929931°
mean anomaly M: 229.875487°
perihelion passage TP: 2117 Jan 29
Epoch: 2014 May 23
data arc: 2001-2009 (48 obs.)
Earth MOID: 40.9585 AU
Jupiter Tisserand invariant TJ: 5.88
Neptune Tisserand invariant TN:3.092 [*D]


orbital data, secondary:
semimajor axis as: 9310 ± 50 km [G11a]
separation/primary radius as/rp:110 [*D]
separation/Hill radius as/rH:0.012 [*D]
orbital period Ps: 125.58 ± 0.05 d [G11a]
eccentricity es: 0.556 ± 0.005 [G11a]
inclination is:41.1° ± 0.2° [G11a]
ascending node Ωs:341.2° ± 0.3° [G11a]
argument of pericenter ωs:246.3° ± 0.9° [G11a]
mean anomaly M:152° ± 0.3° [G11a]
Epoch:2007 Jul 18.5
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 5.7 [MPC]
6.05 ± 0.15 [V14a]
slope parameter G: (0.15) [*A]
effective diameter dE: 221 ± 41/71 km [V14a]
geometric albedo: 0.136 ± 0.168/0.044 [V14a]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: 1.08x1019 ± 2x1017 kg [G14a]
density ρ: 1 ± 0.96/0.56 g/cm3[V14a]
Hill radius rH: 770000 km [*D]

other data, primary:
diameter dp: 171 ± 32/55 km [V14a]
color index V-I:1.04 ± 0.11 [B08d]
rotation period RPp: ?
amplitude in mag., rotational ΔM: ?
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 140 ± 26/45 km [V14a]
diameter ratio ds/dp: 0.826 ± 0.024 [G09a]
component mag. difference ΔM: 0.415 ± 0.064 [G09a]
color index V-I:1.06± 0.12 [B08d]
rotation period RPs: ?

-- 2001 XR254 --discovery and notes:

Primary discovered 2001 Dec 10 from Mauna Kea Observatory, Hawaii, USA by D. C. Jewitt, S. S. Sheppard, and J. Kleyna.

Companion discovered 2006 Dec 20 using Hubble Space Telescope observations from Hubble Space Telescope. Announced 2007 Mar 14.

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2007-2014, 2015 by Wm. Robert Johnston.
Last modified 23 June 2015.
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