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18646 (1998 ED21)
Classification: Main-belt Asteroid          SPK-ID: 2018646
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 31 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1058893314514472 2.8902e-08  
a 2.363090421856966 7.937e-09 au
q 2.112864356927214 6.7578e-08 au
i 8.887722031286547 4.0385e-06 deg
node 157.2881438265555 2.0588e-05 deg
peri 295.9188859486723 2.8904e-05 deg
M 208.7031825614795 2.0316e-05 deg
tp 2459954.130126105103
(2023-Jan-09.63012611)
7.5776e-05 TDB
period 1326.841164252583
3.63
6.6847e-06
1.83e-08
d
yr
n .2713210968268308 1.3669e-09 deg/d
Q 2.613316486786719 8.7774e-09 au
  Orbit Determination Parameters
   # obs. used (total)      1495  
   data-arc span      12539 days (34.33 yr)  
   first obs. used      1987-02-23  
   last obs. used      2021-06-23  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .52009  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Jul-08 18:02:44  

Additional Information
 Earth MOID = 1.14676 au 
 Jupiter MOID = 2.53258 au 
 T_jup = 3.526 
[ 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 14.8   n/a MPO467912  
diameter diameter 4.386 km 0.163 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.084   0.011 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

18646 (1998 ED21)          Discovered 1998-Mar-03 by Elst, E. W. at La Silla
Reference: 20001111/Numbers.arcLast Updated: 2004-04-19

Alternate Designations
 1998 ED21 = 1987 DD3 = 1996 RS2 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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