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21085 (1991 UL4)
Classification: Main-belt Asteroid          SPK-ID: 2021085
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 27 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2246571548454233 4.0984e-08  
a 2.674918857416613 1.1654e-08 au
q 2.073979197467026 1.139e-07 au
i 4.884733128596758 3.6512e-06 deg
node 75.55946215807977 4.8997e-05 deg
peri 316.5071042876418 4.9667e-05 deg
M 285.9512260682146 9.5558e-06 deg
tp 2459725.184872756558
(2022-May-25.68487276)
4.3873e-05 TDB
period 1597.954265945913
4.37
1.0443e-05
2.859e-08
d
yr
n .2252880496469636 1.4724e-09 deg/d
Q 3.2758585173662 1.4273e-08 au
  Orbit Determination Parameters
   # obs. used (total)      1112  
   data-arc span      15559 days (42.60 yr)  
   first obs. used      1978-11-29  
   last obs. used      2021-07-05  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .52048  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Jul-09 10:11:59  

Additional Information
 Earth MOID = 1.08278 au 
 Jupiter MOID = 2.16991 au 
 T_jup = 3.337 
[ 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 15.09   n/a E2021B10  
diameter diameter 5.059 km 0.222 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.069   0.014 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

21085 (1991 UL4)          Discovered 1991-Oct-18 by Ueda, S., Kaneda, H. at Kushiro
Reference: 20010208/Numbers.arcLast Updated: 2004-04-19

Alternate Designations
 1991 UL4 = 1978 WW1 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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