Asteroids with Satellites Database--Johnston's Archive

(12326) Shirasaki

compiled by Wm. Robert Johnston
last updated 19 February 2017

--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: 2.2630859193 AU
orbital period P: 3.404486087 yr
(= 1243.5120287 d)
eccentricity e: 0.187820509
perihelion distance q: 1.83803197 AU
aphelion distance Q: 2.6881398678 AU
inclination i: 5.8417779°
argument of perihelion ω: 17.149225°
ascending node Ω: 3.010704°
mean anomaly M: 48.279715°
perihelion passage TP: 2016 Sep 02.232204
Epoch: 2017 Feb 16
data arc: 1975-2017 (1072 obs.)
Earth MOID: 0.841442 AU
Jupiter Tisserand invariant TJ: 3.588


orbital data, secondary:
semimajor axis as: 8.4 km [*E]
separation/primary radius as/rp:4.5 [*E]
separation/Hill radius as/rH:0.016 [*E]
orbital period Ps: 1.044 d [W17a]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 14.7 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 3.8 km [*E]
geometric albedo:
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 530 km [*E]

other data, primary:
diameter dp: 3.7 km [*E]
rotation period RPp: 2.7286 h [W17a]
amplitude in mag., rotational ΔM: 0.12 [W17a]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 0.9 km [*E]
diameter ratio ds/dp: 0.24 [W17a]
component mag. difference ΔM: ?
rotation period RPs: 12.7 h [W17a]

-- (12326) Shirasaki --discovery and notes:

Primary discovered 1992 Sep 21 from Kitami, Hokkaido, Japan by K. Endate and K. Watanabe. Alternate designation(s): 1992 SF, 1975 TH2, 1994 EE9, 1997 AX24. Linked to prediscovery observations from 1975 Oct 03. Permanent number assigned 1999 Nov 23.

Named 2008 Jun 18 for Shuichi Shirasaki (1958-) [MPC63172].

Companion discovered 2016 Dec 06 by D. Pray, P. Pravec, V. Benishek, J. Oey, and V. Chiorny using lightcurve observations from Sugarloaf Mountain Observatory, South Deerfield, MA; Sopot; Leura; Kharkiv Observatory. Announced 2017 Jan 12 [P17a].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2017 by Wm. Robert Johnston.
Last modified 19 February 2017.
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