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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 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 22 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2310666689998023 3.1796e-08  
a 2.989047059528316 1.5563e-08 au
q 2.298377911999455 1.0059e-07 au
i 9.558226105563287 5.121e-06 deg
node 178.114596258197 1.8708e-05 deg
peri 269.706426567374 2.2041e-05 deg
M 315.8856061311838 1.1818e-05 deg
tp 2459431.799860817378
(2021-Aug-05.29986082)		 6.2688e-05 TDB
period 1887.546049977964
5.17		 1.4742e-05
4.036e-08		 d
yr
n .1907238236673499 1.4896e-09 deg/d
Q 3.679716207057178 1.9159e-08 au
   Orbit Determination Parameters
   # obs. used (total)      1387  
   data-arc span      14578 days (39.91 yr)  
   first obs. used      1981-02-12  
   last obs. used      2021-01-11  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .48185  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Feb-24 02:45:29  

Additional Information
 Earth MOID = 1.33814 au 
 Jupiter MOID = 1.70329 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 14.10   n/a E2021B10  

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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