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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 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 31 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2955069962646629 4.4719e-08  
a 2.428959120982772 7.8835e-09 au
q 1.711184707091497 1.1002e-07 au
i 20.37471800711134 4.4641e-06 deg
node 262.5378251047704 1.1668e-05 deg
peri 255.6281889120312 1.3567e-05 deg
M 326.1507920662243 8.3943e-06 deg
tp 2459330.509397440285
(2021-Apr-26.00939744)
3.2487e-05 TDB
period 1382.702459982848
3.79
6.7316e-06
1.843e-08
d
yr
n .2603597016848192 1.2675e-09 deg/d
Q 3.146733534874046 1.0213e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2010  
   data-arc span      13954 days (38.20 yr)  
   first obs. used      1983-01-06  
   last obs. used      2021-03-21  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .4046  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-May-04 02:45:51  

Additional Information
 Earth MOID = .839243 au 
 Jupiter MOID = 2.31843 au 
 T_jup = 3.366 
[ 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 13.25   n/a MPCxxxxx  
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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