Asteroids with Satellites Database--Johnston's Archive

(31450) 1999 CU9

compiled by Wm. Robert Johnston
last updated 27 November 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: main belt asteroid


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 2.393174608 AU
orbital period P: 3.702214517 yr
(= 1352.2593909 d)
eccentricity e: 0.26751947
perihelion distance q: 1.7529538 AU
aphelion distance Q: 3.03339541 AU
inclination i: 10.751177°
argument of perihelion ω: 18.613811°
ascending node Ω: 324.028204°
mean anomaly M: 342.2260717°
perihelion passage TP: 2015 Sep 01.7637820
Epoch: 2015 Jun 27
data arc: 1967-2015 (1061 obs.)
Earth MOID: 0.747613 AU
Jupiter Tisserand invariant TJ: 3.458


orbital data, secondary:
semimajor axis as: 39 km [*E]
separation/primary radius as/rp:7.5 [*D]
separation/Hill radius as/rH:0.027 [*D]
orbital period Ps: 2.228 ± 0.003 d [P15g]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 13.2 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 10.62 ± 0.19 km [M11b]
geometric albedo: 0.052 ± 0.017 [M11b]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 1400 km [*E]

other data, primary:
diameter dp: 10.4 km [*D]
rotation period RPp: 3.4116 ± 0.0003 h [P15g]
amplitude in mag., rotational ΔM: 0.24 [P15g]
amplitude in mag., mutual events ΔM:0.05 [P15g]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 2.3 km [*D]
diameter ratio ds/dp: 0.22 [P15g]
component mag. difference ΔM: 3.3 [*D]
rotation period RPs: ?

-- (31450) 1999 CU9 --discovery and notes:

Primary discovered 1999 Feb 14 from Reedy Creek by J. Broughton. Alternate designation(s): 1999 CU9, 1926 PF, 1937 OA, 1967 TN. Linked to prediscovery observations from 1967 Oct 09. Permanent number assigned 2001 Nov 30.

Companion discovered 2015 Sep 05 by D. Pray, P. Pravec, K. Hornoch, J. Vrastil, H. Kucakova, V. Benishek, R. Roy, R. Behrend, D. Romeuf, B. Warner, A. Scholz, G. Hodosan, J. Pollock, R. Montaigut, A. Leroy, D. Reichart, and J. Haislip using lightcurve observations from Sugarloaf Mountain Observatory, South Deerfield, Massachusetts, USA; Ondrejov Observatory; Belgrade Astronomical Observatory, Serbia; Observatoirede Blauvac, France; Geneva Observatory; Chapdes-Beaufort, France; Center for Solar System Studies, Eaton, Colorado, USA; Observatory of the University of St. Andrews, UK; Appalachian State University, USA; OPERA Observatory, France; University of North Carolina, Chapel Hill, North Carolina, USA. Announced 2015 Oct 26 [P15g].

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© 2015 by Wm. Robert Johnston.
Last modified 27 November 2015.
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