Asteroids with Satellites Database--Johnston's Archive

2001 XP254

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, 3:5 resonance


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 42.564 AU
orbital period P: 277.696 yr
(= 101428.4 d)
eccentricity e: 0.22369
perihelion distance q: 33.0426 AU
aphelion distance Q: 52.085 AU
inclination i: 2.60021°
argument of perihelion ω: 181.125°
ascending node Ω: 304.9353°
mean anomaly M: 359.217°
perihelion passage TP: 2014 Dec 29
Epoch: 2014 May 23
data arc: 2001-2013 (22 obs.)
Earth MOID: 32.0579 AU
Jupiter Tisserand invariant TJ: 5.692
Neptune Tisserand invariant TN:3.02 [*D]


orbital data, secondary:
semimajor axis as: 1200 ± 100 km (separation) [G12b]
separation/primary radius as/rp:22 [*E]
separation/Hill radius as/rH:0.0046 [*E]
orbital period Ps: 12 d [*E]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 7.6 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 133 km [*E]
geometric albedo: (0.09 ) [*A]
color index U-B: ?
color index B-V: 1.09 [S12f]
color index V-R:0.62 ± 0.03 [S12f]
color index B-R:1.71 ± 0.04 [S12f]
color index V-I:1.22 [S12f]
taxonomic type: ?
mass m: ?
density ρ: (1 g/cm3) [*A]
Hill radius rH: 260000 km [*E]

other data, primary:
diameter dp: 108 km [*E]
rotation period RPp: ?
amplitude in mag., rotational ΔM: ?
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 77 km [*E]
diameter ratio ds/dp: 0.711 [G12b]
component mag. difference ΔM: 0.74 [G12b]
rotation period RPs: ?

-- 2001 XP254 --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 2008 Nov 11 using Hubble Space Telescope observations from Hubble Space Telescope. Announced 2011.

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2011-2013, 2014 by Wm. Robert Johnston.
Last modified 20 September 2014.
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