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16912 Rhiannon (1998 EP8)
Classification: Amor [NEO]          SPK-ID: 2016912
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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Orbit Diagram
Note: Make sure you have Java enabled on your browser to see the applet. This applet is provided as a 3D orbit visualization tool. The applet was implemented using 2-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances. For accurate long-term ephemerides, please instead use our Horizons system.

Note: If the applet has stopped working because of a recent Java upgrade, here is a possible workaround.
Orbit Viewer

Additional Notes: the orbits shown in the applet are color coded. The planets are white lines, and the asteroid/comet is a blue line. The bright white line indicates the portion of the orbit that is above the ecliptic plane, and the darker portion is below the ecliptic plane. Likewise for the asteroid/comet orbit, the light blue indicates the portion above the ecliptic plane, and the dark blue the portion below the ecliptic plane.

Orbit Viewer applet originally written and kindly provided by Osamu Ajiki (AstroArts), and further modified by Ron Baalke (JPL).

Orbital Elements at Epoch 2457600.5 (2016-Jul-31.0) TDB
Reference: JPL 40 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2724722477295903 1.1055e-07  
a 1.751330032347034 1.0172e-08 au
q 1.274141201917102 1.9471e-07 au
i 24.52629561328932 1.346e-05 deg
node 169.2210497340341 1.9271e-05 deg
peri 221.1280242765397 2.7091e-05 deg
M 88.95887757630176 3.14e-05 deg
tp 2457391.311785310479
7.2262e-05 JED
period 846.545722473111
n .4252575973667326 3.7049e-09 deg/d
Q 2.228518862776967 1.2943e-08 au
  Orbit Determination Parameters
   # obs. used (total)      142  
   data-arc span      8469 days (23.19 yr)  
   first obs. used      1992-08-29  
   last obs. used      2015-11-06  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-BIG16  
   condition code      0  
   fit RMS      .61211  
   data source      ORB  
   producer      Otto Matic  
   solution date      2015-Nov-30 16:24:58  

Additional Information
 Earth MOID = .321051 au 
 Jupiter MOID = 3.30329 au 
 T_jup = 3.987 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 17.9 mag n/a MPO344437  

16912 Rhiannon           Discovered 1998 Mar. 2 by ODAS at Caussols.
Rhiannon was a version of the celtic horse-goddess Epona and of sovereignty. She was mistress of the Singing Birds. Sometimes she appeared as a beautiful woman in dazzling gold on a white horse.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20010309/MPCPages.arcLast Updated: 2009-05-11

[ show close-approach data ]
Alternate Designations
 1998 EP8 = 1999 RN45 
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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