Asteroids with Satellites Database--Johnston's Archive

(4092) Tyr

compiled by Wm. Robert Johnston
last updated 9 October 2021

--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: 2.6323671916 AU
orbital period P: 4.2709029617 yr
(= 1559.9767688 d)
eccentricity e: 0.250605666
perihelion distance q: 1.972681058 AU
aphelion distance Q: 3.2920533247 AU
inclination i: 4.02583068°
argument of perihelion ω: 108.6027223°
ascending node Ω: 253.8247805°
mean anomaly M: 321.9044852°
perihelion passage TP: 2020 Nov 12.078106
Epoch: 2020 May 31
data arc: 1997-2020 (2536 obs.)
Earth MOID: 0.974767 AU
Jupiter Tisserand invariant TJ: 3.35


orbital data, secondary:
semimajor axis as: 13 km [*E]
separation/primary radius as/rp:3.9 [*E]
separation/Hill radius as/rH:0.011 [*E]
orbital period Ps: 0.670313 ± 0.000022 d [B20a]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 13.25 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 7.4 km [*E]
geometric albedo: (0.16 ) [*A]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: 2.1 g/cm3[B20a]
Hill radius rH: 1200 km [*E]

other data, primary:
diameter dp: 6.7 km [*E]
rotation period RPp: 16.0875 ± 0.0005 h [B20a]
amplitude in mag., rotational ΔM: 0.52 ± 0.01 [B20a]
amplitude in mag., mutual events ΔM:0.2 ±0.03 [R20a]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 3.0 km [*E]
diameter ratio ds/dp: >0.45 [R20a]
component mag. difference ΔM: <1.73 [*D]
rotation period RPs: 16.0875 ± 0.0005 h [B20a]

-- (4092) Tyr --discovery and notes:

Primary discovered 1986 Oct 08 from Brorfelde, Denmark by P. Jensen. Alternate designation(s): 1986 TJ4, 1956 RG, 1973 QG1. Linked to prediscovery observations from 1956. Permanent number assigned 1989 Apr 20.

Named 1993 Sep 01 for the Norse mythological god [MPC022500].

Companion discovered 2020 Aug 21 by D. Romeuf, R. Behrend, D. Augustin, and E. Barbotin using lightcurve observations. Announced 2020 Sep 17 [R20a].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2020, 2021 by Wm. Robert Johnston.
Last modified 9 October 2021.
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