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90690 (1981 EK31)
Classification: Main-belt Asteroid          SPK-ID: 2090690
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 20 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .08987710589049983 6.9338e-08  
a 2.6232180368634 1.7813e-08 au
q 2.387450791590359 1.7966e-07 au
i 10.21316781297593 6.7505e-06 deg
node 350.4119043077276 3.0172e-05 deg
peri 20.58305127971822 4.1406e-05 deg
M 250.2086065059852 3.0054e-05 deg
tp 2459473.777445350705
(2021-Sep-16.27744535)
0.00013082 TDB
period 1551.85096849638
4.25
1.5807e-05
4.328e-08
d
yr
n .2319810389710369 2.3629e-09 deg/d
Q 2.858985282136441 1.9414e-08 au
  Orbit Determination Parameters
   # obs. used (total)      582  
   data-arc span      13933 days (38.15 yr)  
   first obs. used      1981-02-12  
   last obs. used      2019-04-07  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .59784  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Feb-23 22:16:17  

Additional Information
 Earth MOID = 1.38855 au 
 Jupiter MOID = 2.57225 au 
 T_jup = 3.375 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 15.3   n/a MPO337936  
diameter diameter 3.887 km 0.271 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.117   0.021 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

90690 (1981 EK31)          Discovered 1981-Mar-02 by Bus, S. J. at Siding Spring
Reference: 20041028/Numbers.arcLast Updated: 2004-10-29

Alternate Designations
 1981 EK31 = 2000 WQ6 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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