Asteroids with Satellites Database--Johnston's Archive

(3912) Troja

compiled by Wm. Robert Johnston
last updated 24 Oct 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: 2.3764377616 AU
orbital period P: 3.663514116 yr
(= 1338.098531 d)
eccentricity e: 0.030612717
perihelion distance q: 2.303688546 AU
aphelion distance Q: 2.4491869774 AU
inclination i: 2.40189097°
argument of perihelion ω: 59.864529°
ascending node Ω: 26.1369466°
mean anomaly M: 254.480629°
perihelion passage TP: 2022 Jul 28.20921
Epoch: 2021 Jul 01
data arc: 1937-2021 (3052 obs.)
Earth MOID: 1.32072 AU
Jupiter Tisserand invariant TJ: 3.539


orbital data, secondary:
semimajor axis as: 10 km [*E]
separation/primary radius as/rp:3.6 [*E]
separation/Hill radius as/rH:0.010 [*E]
orbital period Ps: 0.72379 ± 0.00012 d [B21h]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 13.21 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 5.93 ± 0.16 km [M**]
geometric albedo: 0.328 ± 0.028 [M**]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 1000 km [*E]

other data, primary:
diameter dp: 5.63 ± 0.15 km [*D]
rotation period RPp: 3.65938 ± 0.00007 h [B21h]
amplitude in mag., rotational ΔM: 0.18 [B21h]
amplitude in mag., mutual events ΔM:0.125 ±0.015 [B21h]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 1.86 ± 0.12 km [*D]
axial ratios a/b, b/c:1.4;? [B21h]
diameter ratio ds/dp: 0.33 ± 0.02 [B21h]
component mag. difference ΔM: 2.41 ± 0.13 [*D]
rotation period RPs: 17.371 ± 0.003 h [B21h]

-- (3912) Troja --discovery and notes:

Primary discovered 1988 Sep 16 from Haute Provence, France by E. W. Elst. Alternate designation(s): 1988 SG, 1937 VJ, 1970 SZ, 1970 WK, 1977 RE9, 1981 UC14, 1985 XD. Linked to prediscovery observations from 1937 Nov 07. Permanent number assigned 1988 Oct 25.

Named 1989 Feb 20 for the ancient Greek city [MPC014208].

Companion discovered 2021 Sep 07 by V. Benishek, P. Pravec, and R. Durkee using lightcurve observations from Sopot Observatory, Serbia; Shed of Science South Observatory, Pontotoc, Texas, USA. Announced 2021 Oct 22 [B21h].

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--Links to ADS abstracts:


© 2021 by Wm. Robert Johnston.
Last modified 24 Oct 2021.
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