Asteroids with Satellites Database--Johnston's Archive

(8930) Kubota

compiled by Wm. Robert Johnston
last updated 31 October 2025

--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: 2.21268792826 AU
orbital period P: 3.29145901752 yr
(= 1202.20540615 d)
eccentricity e: 0.19222311597
perihelion distance q: 1.78735816 AU
aphelion distance Q: 2.63801769651 AU
inclination i: 4.252400465°
argument of perihelion ω: 81.28502081°
ascending node Ω: 280.75038147°
mean anomaly M: 15.11644716°
perihelion passage TP: 2025 Oct 01.5192375
Epoch: 2025 Nov 21
data arc: 1979-2025 (4168 obs.)
Earth MOID: 0.789426 AU
Jupiter Tisserand invariant TJ: 3.628

orbital data, secondary:
semimajor axis as: 8.6 km [*E]
separation/primary radius as/rp:4.7 [*E]
separation/Hill radius as/rH:0.017 [*E]
orbital period Ps: 1.0796 ± 0.0008 d [D25c]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 14.16 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 3.97 ± 0.1 km [M19a]
geometric albedo: 0.338 ± 0.054 [M19a]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 520 km [*E]

other data, primary:
diameter dp: 3.63 ± 0.09 km [*D]
axial ratios a/b, b/c:1.1, ? [*E]
rotation period RPp: 3.5867 ± 0.0003 h [D25c]
amplitude in mag., rotational ΔM: 0.08 [D25c]
amplitude in mag., mutual events ΔM:0.19 [D25c]
pole direction Β, λ: ? , ?

other data, secondary:
diameter ds: 1.60 ± 0.08 km [*D]
diameter ratio ds/dp: 0.44 ± 0.02 [D25c]
component mag. difference ΔM: 1.78 ± 0.10 [*D]
rotation period RPs: ?

-- (8930) Kubota --discovery and notes:

Primary discovered 1997 Jan 06 from Oizumi, Gunma, Japan by T. Kobayashi. Alternate designation(s): 1997 AX3, 1979 WN4, 1989 WL3, 1992 PD5. Linked to prediscovery observations from 1979 Nov 17. Permanent number assigned 1998 Jun 10.

Named 2003 Nov 09 for Takashi Kubota (1960-) [MPC050249].

Companion discovered 2025 Sep 24 by R. Durkee, P. Pravec, V. Benishek, F. Vachier, R. Goncalves, N. Ruocco, A. Galad, A. Klotz, J. Berthier, and P. Thierry using lightcurve observations from Shed of Science South Observatory, Pontotoc, Texas, USA; Sopot Observatory, Serbia; Observatoire des Makes, Reunion, France; Linhaceira Observatory, Tomar, Portugal; Osservatorio Astronomico Nastro Verde, Sorrento, Italy; Modra Observatory, Slovakia. Announced 2025 Oct 30 [D25c].

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© 2025 by Wm. Robert Johnston.
Last modified 31 October 2025.
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