Asteroids with Satellites Database--Johnston's Archive
(1656)
Suomi
compiled by Wm. Robert Johnston
last updated
11 October 2020
--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:
Mars crossing asteroid
orbital data, primary (osculating elements)
[JPL]
: |
semimajor axis a: |
1.8778819257 AU
| |
orbital period P: |
2.5733711212 yr
(= 939.915539 d)
| |
eccentricity e: |
0.123171623
| |
perihelion distance q: |
1.646580161 AU
| |
aphelion distance Q: |
2.1091836901 AU
| |
inclination i: |
25.0658521°
| |
argument of perihelion ω: |
287.499175°
| |
ascending node Ω: |
175.5387855°
| |
mean anomaly M: |
197.748597°
| |
perihelion passage TP: |
2021 Jul 28.630099
| |
Epoch: |
2020 May 31
| |
data arc: |
1942-2020
(2393 obs.)
| |
Earth MOID: |
0.754228 AU
| |
Jupiter Tisserand invariant TJ: |
3.851
|
orbital data, secondary:
|
semimajor axis as: |
30
km
[*E]
| |
separation/primary radius as/rp: | 7.9 [*E] | |
separation/Hill radius as/rH: | 0.031 [*E] | |
orbital period Ps: |
2.413
± 0.001
d [W20c]
| |
eccentricity es: |
?
| |
normalized ang. mom. αL: |
?
|
|
other data, system (combined):
|
absolute mag. H: |
12.8
[MPC]
| |
slope parameter G: |
(0.15) [*A]
| |
effective diameter dE: |
7.86
± 0.7
km [JPL]
| |
geometric albedo: |
0.156
± 0.032
[JPL]
| |
color index U-B: |
?
| |
color index B-V: |
?
| |
taxonomic type: |
S (Tholen) [JPL]
| |
mass m: |
?
| |
density ρ: |
(1.6
g/cm3) [*A]
| |
Hill radius rH: |
980 km [*E]
|
other data, primary:
|
diameter dp: |
7.61
km [*D]
| |
rotation period RPp: |
2.5885
± 0.0001
h [W20c]
| |
amplitude in mag., rotational ΔM: |
0.11
± 0.01
[W20c]
| |
amplitude in mag., mutual events ΔM: | 0.07 ±0.01 [W20c] | |
pole direction Β, λ: |
?
,
?
|
other data, secondary:
|
diameter ds: |
>1.98
km [*D]
| |
diameter ratio ds/dp: |
>0.26
± 0.02
[W20c]
| |
component mag. difference ΔM: |
<2.9
[*D]
| |
rotation period RPs: |
?
| |
|
|
--
(1656) Suomi
--discovery and notes:
Primary discovered
1942 Mar 11
from
Turku, Finland
by
Y. Vaisala.
Alternate designation(s):
1942 EC,
1955 HL.
Linked to prediscovery observations from 1942 Mar 10.
Permanent number assigned -.
Named 1976 Feb 20 [MPC003932].
Companion discovered
2020 Jun 09
by B. D. Warner, R. D. Stephens, and A. W. Harris
using
lightcurve
observations from Center for Solar System Studies, Landers, California, USA.
Announced
2020 Sep [W20c].
--Links, more technical:
--Links, less technical:
--Links to ADS abstracts:
©
2020
by Wm. Robert Johnston.
Last modified
11 October 2020
Return to Home. Return to Astronomy and Space. Return to Asteroids with Satellites.