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JPL Small-Body Database Browser
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18640 (1998 EF9)
Classification: Main-belt Asteroid          SPK-ID: 2018640
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2458600.5 (2019-Apr-27.0) TDB
Reference: JPL 20 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2956460148067983 4.5224e-08  
a 2.428029056498487 1.2952e-08 au
q 1.710191942109599 1.1144e-07 au
i 20.37620857499349 4.6462e-06 deg
node 262.5351443444668 1.414e-05 deg
peri 255.7134778628207 1.7168e-05 deg
M 169.7838969376172 1.4974e-05 deg
tp 2457948.761700591658
(2017-Jul-14.26170059)
5.3622e-05 TDB
period 1381.908367159286
3.78
1.1057e-05
3.027e-08
d
yr
n .2605093134648518 2.0844e-09 deg/d
Q 3.145866170887375 1.6781e-08 au
  Orbit Determination Parameters
   # obs. used (total)      1463  
   data-arc span      13475 days (36.89 yr)  
   first obs. used      1983-01-06  
   last obs. used      2019-11-28  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .43557  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-Dec-03 23:53:12  

Additional Information
 Earth MOID = .838869 au 
 Jupiter MOID = 2.32125 au 
 T_jup = 3.367 
[ 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 13.2   n/a MPO502310  
diameter diameter 6.727 km 0.060 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.271   0.044 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

18640 (1998 EF9)          Discovered 1998-Mar-07 by Beijing Schmidt CCD Asteroid Program at Xinglong
Reference: 20001111/Numbers.arcLast Updated: 2004-04-19

Alternate Designations
 1998 EF9 = 1983 AT6 = 1999 NL45 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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