Asteroids with Satellites Database--Johnston's Archive

1998 WW31 and S/2000 (1998 WW31) 1

compiled by Wm. Robert Johnston
last updated 3 May 2014
under construction--testing upgrades!

--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: 44.816 AU
orbital period P: 300.023 yr (= 109583.3 d)
eccentricity e: 0.08211
perihelion distance q: 41.136 AU
aphelion distance Q: 48.496 AU
inclination i: 6.78897°
argument of perihelion ω: 52.56°
ascending node Ω: 237.07985°
mean anomaly M: 133.78°
perihelion passage TP: 1902 Nov 24
Epoch: 2014 May 23
data arc: 1998-2011 (32 obs.)
Earth MOID: 40.1235 AU
Jupiter Tisserand invariant TJ: 5.925
Neptune Tisserand invariant TN:3.09 [*D]


orbital data, secondary:
semimajor axis as: 22620 ± 40 km [G14a]
separation/primary radius as/rp:310 [*D]
separation/Hill radius as/rH:0.048 [*D]
orbital period Ps: 587.3 ± 0.2 d [G14a]
eccentricity es: 0.819 ± 0.002 [G14a]
inclination is:41.7°± 7[*V02a]
ascending node Ωs:94.3°± 8[*V02a]
argument of pericenter ωs:235.8°± 7[*V02a]
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 6.7 [MPC]
slope parameter G: 0.15 [*A]
effective diameter dE: 192 km [*D]
geometric albedo: 0.054 ± 0.005 [V02a]
color index U-B: ?
color index B-V: ?
color index R-J:1.49± 0.21 [T03a]
color index J-H:0.34± 0.23 [T03a]
taxonomic type: ?
mass m: 2.67x1018 kg [V02a]
density ρ: 1 g/cm3 [V02a]
Hill radius rH: 470000 km [*D]

other data, primary:
diameter dp: 148 km [V02a]
rotation period RPp: ?
amplitude in mag., rotational ΔM: ?
pole direction : ? ; ?


other data, secondary:
diameter ds: 123 km [V02a]
diameter ratio ds/dp: 0.833 [V02a]
component mag. difference ΔM: ?
rotation period RPs: ?

-- 1998 WW31 and S/2000 (1998 WW31) 1 --discovery and notes:

Primary discovered 1998 Nov 18 from Kitt Peak Observatory, Arizona, USA by M. W. Buie.

Companion discovered 2000 Dec 22 by C. Veillet, A. Doressoudiram, and J. Shapiro using IMG observations from CFHT Telescope, Mauna Kea, Hawaii, USA. Announced 2001 Apr 16 [I7610]. Provisional designation S/2000 (1998 WW31) 1.

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2001-2006, 2014 by Wm. Robert Johnston.
Last modified 3 May 2014.
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