Asteroids with Satellites Database--Johnston's Archive

(1089) Tama

compiled by Wm. Robert Johnston
last updated 21 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: main belt asteroid

orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 2.213775091 AU
orbital period P: 3.293885112 yr
(= 1203.0915370 d)
eccentricity e: 0.127502720
perihelion distance q: 1.931512745 AU
aphelion distance Q: 2.496037438 AU
inclination i: 3.7266981°
argument of perihelion ω: 354.353642°
ascending node Ω: 71.499243°
mean anomaly M: 83.705140°
perihelion passage TP: 2013 Aug 16.26403
Epoch: 2014 May 23
data arc: 1904-2014 (1551 obs.)
Earth MOID: 0.944211 AU
Jupiter Tisserand invariant TJ: 3.642

orbital data, secondary:
binary dynamical type:B [P07f]
semimajor axis as: 20.7 ± 1.3 km [B06a]
separation/primary radius as/rp:1.95 [B06a]
separation/Hill radius as/rH:0.014 [*D]
orbital period Ps: 0.6852 ± 0.00004 d [B06a]
eccentricity es: ?
normalized ang. mom. αL: 1.28 [P07f]

other data, system (combined):
absolute mag. H: 11.7 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 12.92 ± 0.6 km [T04c]
geometric albedo: 0.242 ± 0.023 [T04c]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: 8.9x1014 ± 3.2x1014 kg [B06a]
density ρ: 2.52 ± 0.3 g/cm3[B06a]
Hill radius rH: 1500 km [*D]

other data, primary:
diameter dp: 10.7 ± 0.5 km [*D]
rotation period RPp: 16.444 ± 0.001 h [B06a]
amplitude in mag., rotational ΔM: 0.41 ± 0.01 [B06a]
amplitude in mag., mutual events ΔM:0.55 ±0.03 [B06a]
pole direction Β, λ: ? , ?

other data, secondary:
diameter ds: 7.33 km [*D]
diameter ratio ds/dp: 0.685 [B06a]
component mag. difference ΔM: 0.82 [*D]
rotation period RPs: ?

-- (1089) Tama --discovery and notes:

Primary discovered 1927 Nov 17 from Tokyo, Japan by O. Oikawa. Alternate designation(s): 1927 WB, 1930 ST, 1952 HE4, A894 VA, A904 VD, A919 HA. Linked to prediscovery observations from 1904 Nov 15. Permanent number assigned -.

Named - for the Tama River, Honshu, Japan.

Companion discovered 2003 Dec 24 by R. Behrend, R. Roy, C. Rinner, P. Antonini, P. Pravec, A. W. Harris, S. Sposetti, R. Durkee, and A. Klotz using lightcurve observations from Geneva Observatory; Blauvac, France; Ottmarsheim, France; Bedoin, France; Ondrejov Observatory, Czech Republic; Space Science Institute; Gnosca, Switzerland; Shed of Science Observatory, Minneapolis, Minnesota, USA; Guitalens, France. Announced 2004 Jan 12 [B04b].

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--Links to ADS abstracts:

© 2004-2006, 2014 by Wm. Robert Johnston.
Last modified 21 September 2014.
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