Asteroids with Satellites Database--Johnston's Archive

(53432) 1999 UT55

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: Mars crossing asteroid, Hungaria


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 1.871650083 AU
orbital period P: 2.560620330 yr
(= 935.266575 d)
eccentricity e: 0.11587349
perihelion distance q: 1.65477546 AU
aphelion distance Q: 2.088524707 AU
inclination i: 22.438208°
argument of perihelion ω: 126.671892°
ascending node Ω: 268.739716°
mean anomaly M: 242.524920°
perihelion passage TP: 2015 Mar 24.1958
Epoch: 2014 May 23
data arc: 1994-2013 (308 obs.)
Earth MOID: 0.7172 AU
Jupiter Tisserand invariant TJ: 3.881


orbital data, secondary:
semimajor axis as: 4 km [*E]
separation/primary radius as/rp:3.1 [*E]
separation/Hill radius as/rH:0.012 [*E]
orbital period Ps: 0.5875 ± 0.0004 d [W13d]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 15.5 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 2.62 km [*E]
geometric albedo: (0.16 ) [*A]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 330 km [*E]

other data, primary:
diameter dp: 2.55 km [*E]
rotation period RPp: 3.330 ± 0.002 h [W13d]
amplitude in mag., rotational ΔM: 0.10 ± 0.01 [W13d]
amplitude in mag., mutual events ΔM:0.10 ±0.04 [W13d]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 0.59 km [*E]
diameter ratio ds/dp: >0.23 ± 0.02 [W13d]
component mag. difference ΔM: <3.2 ± 0.2 [*D]
rotation period RPs: ?

-- (53432) 1999 UT55 --discovery and notes:

Primary discovered 1999 Oct 19 from Socorro, New Mexico, USA by LINEAR. Alternate designation(s): 1994 WO12, 2000 AU3. Linked to prediscovery observations from 1994 Nov 28. Permanent number assigned 2003 Feb 16.

Companion discovered 2013 Jan 03 using lightcurve observations. Announced 2013 Feb .

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


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