Asteroids with Satellites Database--Johnston's Archive
(163693)
Atira
compiled by Wm. Robert Johnston
last updated
19 February 2017
--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, Atira
orbital data, primary (osculating elements)
[JPL]
: |
semimajor axis a: |
0.7410827428 AU
| |
orbital period P: |
0.637969697 yr
(= 233.0228326 d)
| |
eccentricity e: |
0.32216064
| |
perihelion distance q: |
0.502335056 AU
| |
aphelion distance Q: |
0.97983043 AU
| |
inclination i: |
25.617734°
| |
argument of perihelion ω: |
252.931962°
| |
ascending node Ω: |
103.907079°
| |
mean anomaly M: |
132.78882°
| |
perihelion passage TP: |
2016 Nov 22.047703
| |
Epoch: |
2017 Feb 16
| |
data arc: |
2003-2015
(376 obs.)
| |
Earth MOID: |
0.206966 AU
| |
Jupiter Tisserand invariant TJ: |
7.666
|
orbital data, secondary:
|
semimajor axis as: |
6
km
(separation)
[R17a]
| |
separation/primary radius as/rp: | 2.5 [*D] | |
separation/Hill radius as/rH: | 0.032 [*D] | |
orbital period Ps: |
0.646
d [R17a]
| |
eccentricity es: |
?
| |
normalized ang. mom. αL: |
?
|
|
other data, system (combined):
|
absolute mag. H: |
16.3
[MPC]
| |
slope parameter G: |
(0.15) [*A]
| |
effective diameter dE: |
4.9
± 0.5
km [*D]
| |
geometric albedo: |
0.022
[*D]
| |
color index U-B: |
?
| |
color index B-V: |
?
| |
taxonomic type: |
?
| |
mass m: |
?
| |
density ρ: |
(1.6
g/cm3) [*A]
| |
Hill radius rH: |
190 km [*E]
|
other data, primary:
|
diameter dp: |
4.8
± 0.5
km [R17a]
| |
rotation period RPp: |
2.9745
h [JPL]
| |
amplitude in mag., rotational ΔM: |
?
| |
pole direction Β, λ: |
?
,
?
|
other data, secondary:
|
diameter ds: |
1
± 0.3
km [R17a]
| |
diameter ratio ds/dp: |
0.21
± 0.07
[*D]
| |
component mag. difference ΔM: |
3.4
± 0.7
[*D]
| |
rotation period RPs: |
?
| |
|
|
--
(163693) Atira
--discovery and notes:
Primary discovered
2003 Feb 11
from
Socorro, New Mexico, USA
by
LINEAR Program.
Alternate designation(s):
2003 CP20
.
Permanent number assigned 2007 Sep 26.
Named 2008 Jan 22 for the mythological Pawnee goddess of Earth [MPC61768].
Companion discovered
2017 Jan 20
by E. G. Rivera-Valentin, P. A. Taylor, A. Virkki, and B. Aponte-Hernandez
using
radar
observations from Arecibo Observatory, Puerto Rico.
Announced
2017 Jan 28 [R17a].
--Links, more technical:
--Links, less technical:
--Links to ADS abstracts:
©
2017
by Wm. Robert Johnston.
Last modified
19 February 2017.
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