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18306 (1981 EF9)
Classification: Main-belt Asteroid          SPK-ID: 2018306
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 23 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .104534614052835 5.7405e-08  
a 2.308224263951989 8.9739e-09 au
q 2.066934931372379 1.3278e-07 au
i 3.984521952756712 4.1357e-06 deg
node 283.7414037033648 7.5515e-05 deg
peri 262.2265014407331 7.7682e-05 deg
M 58.14201227250086 1.8984e-05 deg
tp 2458793.627392945644
(2019-Nov-06.12739295)
6.7376e-05 TDB
period 1280.900602313549
3.51
7.4698e-06
2.045e-08
d
yr
n .281052252883457 1.639e-09 deg/d
Q 2.549513596531599 9.912e-09 au
  Orbit Determination Parameters
   # obs. used (total)      1270  
   data-arc span      14797 days (40.51 yr)  
   first obs. used      1979-10-18  
   last obs. used      2020-04-22  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .52847  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-May-20 04:47:20  

Additional Information
 Earth MOID = 1.07289 au 
 Jupiter MOID = 2.42822 au 
 T_jup = 3.576 
[ 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 14.9   n/a MPO467907  
diameter diameter 2.617 km 0.271 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.409   0.055 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

18306 (1981 EF9)          Discovered 1981-Mar-01 by Bus, S. J. at Siding Spring
Reference: 20001111/Numbers.arcLast Updated: 2004-04-19

[ show close-approach data ]
Alternate Designations
 1981 EF9 = 2000 SX168 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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