Asteroids with Satellites Database--Johnston's Archive
(31)
Euphrosyne
compiled by Wm. Robert Johnston
last updated
3 May 2022
--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: |
3.1554023036 AU
| |
orbital period P: |
5.6050837663 yr
(= 2047.2955113 d)
| |
eccentricity e: |
0.220857025
| |
perihelion distance q: |
2.458509538 AU
| |
aphelion distance Q: |
3.852295069 AU
| |
inclination i: |
26.3033445°
| |
argument of perihelion ω: |
61.470392°
| |
ascending node Ω: |
31.1185729°
| |
mean anomaly M: |
87.1671452°
| |
perihelion passage TP: |
2017 Dec 17.286374
| |
Epoch: |
2019 Apr 27
| |
data arc: |
1860-2018
(2068 obs.)
| |
Earth MOID: |
1.56992 AU
| |
Jupiter Tisserand invariant TJ: |
3.011
|
orbital data, secondary:
|
semimajor axis as: |
672
± 35 km
[Y20a]
| |
separation/primary radius as/rp: | 5.01 [Y20a] | |
separation/Hill radius as/rH: | 0.013 [*D] | |
orbital period Ps: |
1.209
± 0.003
d [Y20a]
| |
eccentricity es: |
0.043
± 0.123/0.043
[Y20a]
| |
inclination is: | 1.4° ± 1.4° [Y20a] | |
ascending node Ωs: | 80.1° ± 27.9° [Y20a] | |
argument of pericenter ωs: | 135.2° ± 40.5° [Y20a] | |
pericenter passage TP: | 2019 Mar 22.83± 0.13 [Y20a] | |
normalized ang. mom. αL: |
?
|
|
other data, system (combined):
|
absolute mag. H: |
6.74
[MPC]
| |
slope parameter G: |
(0.15) [*A]
| |
effective diameter dE: |
267.08
± 2.61
km [M12b]
| |
geometric albedo: |
0.053
± 0.006
[M12b]
| |
color index U-B: |
0.317
[T95a]
| |
color index B-V: |
0.687
[T95a]
| |
taxonomic type: |
Cb (SMASSII) [JPL]
C (Tholen) [JPL]
| |
mass m: |
1.7x1019
± 3x1018
kg [Y20a]
| |
density ρ: |
1.665
± 0.242
g/cm3[Y20a]
| |
Hill radius rH: |
52000 km [*D]
|
other data, primary:
|
diameter dp: |
268
± 6
km [Y20a]
| |
dimensions : | 294 x 280 x 248km [Y20a] | |
axial ratios a/b, b/c: | 1.05, 1.13 [Y20a] | |
rotation period RPp: |
2.529595
h [W21b]
| |
amplitude in mag., rotational ΔM: |
?
| |
pole direction Β, λ: |
?
,
?
|
other data, secondary:
|
diameter ds: |
4.25
± 0.54
km [*D]
| |
diameter ratio ds/dp: |
0.016
± 0.002
[*D]
| |
component mag. difference ΔM: |
9.0
± 0.3
[Y20a]
| |
rotation period RPs: |
?
| |
|
|
--
(31) Euphrosyne
--discovery and notes:
Primary discovered
1854 Sep 01
from
Washington, USA
by
J. Ferguson.
Alternate designation(s):
A907 GP, A918 GB.
Permanent number assigned 1854.
Named 1854 for the Greek mythological Grace [AN00924].
Companion discovered
2019 Mar 15
by P. Vernazza, B. Carry, F. Vachier, J. Hanus, J. Berthier, B. Yang, F. Marchis, and the HARISSA team
using
adaptive optics telescope
observations from Very Large Telescope, European Southern Observatory, Cerro Paranal, Chile.
Announced
2019 May 17 [V19c].
--Links, more technical:
--Links, less technical:
--Links to ADS abstracts:
©
2019, 2022
by Wm. Robert Johnston.
Last modified
3 May 2022.
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