Asteroids with Satellites Database--Johnston's Archive

(1866) Sisyphus

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: NEA, Apollo


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 1.893818726 AU
orbital period P: 2.606248439 yr
(= 951.9322422 d)
eccentricity e: 0.538293967
perihelion distance q: 0.874387531 AU
aphelion distance Q: 2.913249921 AU
inclination i: 41.18974205°
argument of perihelion ω: 293.0454938°
ascending node Ω: 63.56059474°
mean anomaly M: 352.0426005°
perihelion passage TP: 2014 Jun 13.04140
Epoch: 2014 May 23
data arc: 1955-2013 (2352 obs.)
Earth MOID: 0.103525 AU
Jupiter Tisserand invariant TJ: 3.513


orbital data, secondary:
semimajor axis as: 20 km [*E]
separation/primary radius as/rp:4.7 [*E]
separation/Hill radius as/rH:0.035 [*E]
orbital period Ps: 1.13 d [W17a]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 12.4 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 8.48 ± 1.27 km [D03a]
geometric albedo: 0.15 ± 0.045 [D03a]
color index U-B: ?
color index B-V: ?
taxonomic type: S (SMASSII) [JPL]
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 570 km [*E]

other data, primary:
diameter dp: 8.44 km [*D]
rotation period RPp: 2.3909 h [W17a]
amplitude in mag., rotational ΔM: 0.03 [W17a]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 0.8 km [*D]
diameter ratio ds/dp: 0.1 [W17a]
component mag. difference ΔM: 5
rotation period RPs: ?

-- (1866) Sisyphus --discovery and notes:

Primary discovered 1972 Dec 05 from Zimmerwald, Switzerland by P. Wild. Alternate designation(s): 1972 XA . Linked to prediscovery observations from 1955 Jan 26. Permanent number assigned -.

Named - for the Greek mythological king [MPC3758].

Companion discovered 1985 Dec using radar observations from Arecibo Observatory, Puerto Rico. Announced 2007 Dec .

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2008, 2014, 2017 by Wm. Robert Johnston.
Last modified 19 February 2017.
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