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

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Orbit Diagram
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Note: This Java-based orbit viewer will eventually be retired.

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 two-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 is not working, here are some notes that might help.
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 2459000.5 (2020-May-31.0) TDB
Reference: JPL 55 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2724423269544869 9.1383e-08  
a 1.751313035200946 1.024e-08 au
q 1.274181236665075 1.6329e-07 au
i 24.52006817350998 9.8077e-06 deg
node 169.1817276710607 1.5253e-05 deg
peri 221.2083728038377 2.5422e-05 deg
M 324.2703143154509 3.8082e-05 deg
tp 2459084.517700700035
9.0217e-05 TDB
period 846.5333985597391
n .4252637883071014 3.7299e-09 deg/d
Q 2.228444833736817 1.303e-08 au
  Orbit Determination Parameters
   # obs. used (total)      194  
   data-arc span      9738 days (26.66 yr)  
   first obs. used      1992-08-29  
   last obs. used      2019-04-28  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .59523  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-Sep-24 09:29:25  

Additional Information
 Earth MOID = .322322 au 
 Jupiter MOID = 3.31017 au 
 T_jup = 3.987 
[ show covariance matrix ]

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

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 17.8   n/a MPO416889  

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 | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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