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19945 (1981 ET31)
Classification: Main-belt Asteroid          SPK-ID: 2019945
[ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 18 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2309365240760894 3.499e-08  
a 2.989412429977015 1.9196e-08 au
q 2.299047914368267 1.0655e-07 au
i 9.557280463855294 5.2048e-06 deg
node 178.1149874338589 2.4383e-05 deg
peri 269.6610097020815 2.6971e-05 deg
M 277.7711607568803 1.1984e-05 deg
tp 2459431.719944956721
(2021-Aug-05.21994496)		 6.4636e-05 TDB
period 1887.892150896544
5.17		 1.8184e-05
4.979e-08		 d
yr
n .1906888589102079 1.8367e-09 deg/d
Q 3.679776945585763 2.3629e-08 au
   Orbit Determination Parameters
   # obs. used (total)      989  
   data-arc span      14354 days (39.30 yr)  
   first obs. used      1981-02-12  
   last obs. used      2020-06-01  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .51717  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Jun-23 18:37:38  

Additional Information
 Earth MOID = 1.33909 au 
 Jupiter MOID = 1.70324 au 
 T_jup = 3.195 
[ 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 14.0   n/a MPO449097  

19945 (1981 ET31)          Discovered 1981-Mar-02 by Bus, S. J. at Siding Spring
Reference: 20010109/Numbers.arcLast Updated: 2004-04-19

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Alternate Designations
 1981 ET31 = 1989 TN14 = 1999 RU138 
[ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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