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18754 (1999 GL21)
Classification: Main-belt Asteroid          SPK-ID: 2018754
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 36 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1152718539502434 3.3567e-08  
a 2.395053635485793 9.9059e-09 au
q 2.118971362613076 8.0079e-08 au
i 7.262546283382867 3.7026e-06 deg
node 39.20273758716557 2.8527e-05 deg
peri 252.9156402498766 3.2708e-05 deg
M 182.3396151296309 1.667e-05 deg
tp 2459668.627565312194
(2022-Mar-30.12756531)
6.3133e-05 TDB
period 1353.852315967292
3.71
8.3993e-06
2.3e-08
d
yr
n .265907880611623 1.6497e-09 deg/d
Q 2.671135908358511 1.1048e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2112  
   data-arc span      15167 days (41.52 yr)  
   first obs. used      1978-10-09  
   last obs. used      2020-04-18  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .47954  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-May-20 04:53:11  

Additional Information
 Earth MOID = 1.11668 au 
 Jupiter MOID = 2.48928 au 
 T_jup = 3.510 
[ 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 13.6   n/a MPO452436  
diameter diameter 4.422 km 0.174 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.360   0.072 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

18754 (1999 GL21)          Discovered 1999-Apr-15 by LINEAR at Socorro
Reference: 20001111/Numbers.arcLast Updated: 2004-04-19

Alternate Designations
 1999 GL21 = 1978 TB9 = 1989 UT9 = 2000 ON50 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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