Asteroids with Satellites Database--Johnston's Archive
(1990)
Pilcher
compiled by Wm. Robert Johnston
last updated
23 Apr 2023
--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: |
2.1738042485 AU
| |
orbital period P: |
3.2050798372 yr
(= 1170.6554105 d)
| |
eccentricity e: |
0.051858151
| |
perihelion distance q: |
2.06107478 AU
| |
aphelion distance Q: |
2.2865337173 AU
| |
inclination i: |
3.13482102°
| |
argument of perihelion ω: |
12.796389°
| |
ascending node Ω: |
193.568371°
| |
mean anomaly M: |
285.494231°
| |
perihelion passage TP: |
2023 Oct 25.279393
| |
Epoch: |
2023 Feb 25
| |
data arc: |
1937-2023
(4384 obs.)
| |
Earth MOID: |
1.05665 AU
| |
Jupiter Tisserand invariant TJ: |
3.683
|
orbital data, secondary:
|
semimajor axis as: |
12
km
[*E]
| |
separation/primary radius as/rp: | 3.6 [*E] | |
separation/Hill radius as/rH: | 0.011 [*E] | |
orbital period Ps: |
0.71442
± 0.00008
d [B23j]
| |
eccentricity es: |
?
| |
normalized ang. mom. αL: |
?
|
|
other data, system (combined):
|
absolute mag. H: |
12.91
[MPC]
| |
slope parameter G: |
(0.15) [*A]
| |
effective diameter dE: |
6.75
± 0.17
km [M**]
| |
geometric albedo: |
0.215
± 0.039
[M**]
| |
color index U-B: |
0.504
[JPL]
| |
color index B-V: |
0.85
[JPL]
| |
taxonomic type: |
S (Tholen) [JPL]
| |
mass m: |
?
| |
density ρ: |
(1.6
g/cm3) [*A]
| |
Hill radius rH: |
1100 km [*E]
|
other data, primary:
|
diameter dp: |
6.59
± 0.17
km [*D]
| |
rotation period RPp: |
2.84096
± 0.00007
h [B23j]
| |
amplitude in mag., rotational ΔM: |
0.11
[B23j]
| |
amplitude in mag., mutual events ΔM: | 0.05 [B23j] | |
pole direction Β, λ: |
?
,
?
|
other data, secondary:
|
diameter ds: |
>1.45
km [*D]
| |
diameter ratio ds/dp: |
>0.22
[B23j]
| |
component mag. difference ΔM: |
<3.3
[*D]
| |
rotation period RPs: |
?
| |
|
|
--
(1990) Pilcher
--discovery and notes:
Primary discovered
1956 Mar 09
from
Heidelberg, Germany
by
K. Reinmuth.
Alternate designation(s):
1956 EE,
1937 JL, 1940 FA, 1959 CE1, 1964 VS2, 1972 EC, 1972 GO, 1973 QM.
Linked to prediscovery observations from 1937 May 03.
Permanent number assigned -.
Named 1982 Apr 08 for Frederick Pilcher (1939-) [MPC006833].
Companion discovered
2022 Dec 29
by V. Benishek, P. Pravec, F. Pilcher, M. Husarik, A. Voitko, D. Tomko, M. Pikler, G. Cervak, A. Marchini, and R. Papini
using
lightcurve
observations from Sopot Observatory, Serbia; Organ Mesa Observatory, New Mexico, USA; Skalnate Pleso Observatory; Astronomical Observatory of the University of Siena.
Announced
2023 Apr 22 [B23j].
--Links, more technical:
--Links, less technical:
--Links to ADS abstracts:
©
2023
by Wm. Robert Johnston.
Last modified
23 Apr 2023.
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