Asteroids with Satellites Database--Johnston's Archive
(399307)
1991 RJ2
compiled by Wm. Robert Johnston
last updated
17 January 2015
--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:
NEA, Amor
orbital data, primary (osculating elements)
[JPL]
: |
semimajor axis a: |
2.2083582416 AU
| |
orbital period P: |
3.281740899 yr
(= 1198.6785019 d)
| |
eccentricity e: |
0.428903368
| |
perihelion distance q: |
1.26118595 AU
| |
aphelion distance Q: |
3.1555305285 AU
| |
inclination i: |
8.9433021°
| |
argument of perihelion ω: |
150.817669°
| |
ascending node Ω: |
171.820039°
| |
mean anomaly M: |
37.125057°
| |
perihelion passage TP: |
2014 Aug 07.386090
| |
Epoch: |
2014 Dec 09
| |
data arc: |
1991-2014
(206 obs.)
| |
Earth MOID: |
0.262188 AU
| |
Jupiter Tisserand invariant TJ: |
3.519
|
orbital data, secondary:
|
semimajor axis as: |
0.86
km
[*E]
| |
separation/primary radius as/rp: | 3.4 [*E] | |
separation/Hill radius as/rH: | 0.017 [*E] | |
orbital period Ps: |
0.66321
± 0.00004
d [W15b]
| |
eccentricity es: |
?
| |
normalized ang. mom. αL: |
?
|
|
other data, system (combined):
|
absolute mag. H: |
18.9
[MPC]
| |
slope parameter G: |
(0.15) [*A]
| |
effective diameter dE: |
0.55
km [*E]
| |
geometric albedo: |
(0.16
) [*A]
| |
color index U-B: |
?
| |
color index B-V: |
?
| |
taxonomic type: |
?
| |
mass m: |
?
| |
density ρ: |
(1.6
g/cm3) [*A]
| |
Hill radius rH: |
51 km [*E]
|
other data, primary:
|
diameter dp: |
0.5
km [*E]
| |
rotation period RPp: |
3.4907
± 0.0002
h [W15b]
| |
amplitude in mag., rotational ΔM: |
0.09
[W15b]
| |
amplitude in mag., mutual events ΔM: | 0.35 [W15b] | |
pole direction Β, λ: |
?
,
?
|
other data, secondary:
|
diameter ds: |
0.24
km [*E]
| |
axial ratios a/b, b/c: | 1.07;? [W15b] | |
diameter ratio ds/dp: |
>0.47
± 0.02
[W15b]
| |
component mag. difference ΔM: |
<1.64
[*D]
| |
rotation period RPs: |
15.917
± 0.001
h [W15b]
| |
|
|
--
(399307) 1991 RJ2
--discovery and notes:
Primary discovered
1991 Sep 08
from
Palomar Observatory, California, USA
by
E. F. Helin.
Permanent number assigned 2014 Jul 12.
Companion discovered
2014 Aug 27
by B. D. Warner, J. T. Pollock, D. E. Reichart, J. B. Haislip, A. P. LaCluyze, A. Verveer, T. Spuck, A. W. Harris
using
lightcurve
observations from Palmer Divide Observatory, Colorado Springs, Colorado, USA; PROMPT Telescope, Chile; Perth Observatory, Australia.
Announced
2014 Dec [W15b].
--Links, more technical:
--Links, less technical:
--Links to ADS abstracts:
©
2015, 2014
by Wm. Robert Johnston.
Last modified
17 January 2015.
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