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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 | Close-Approach Data ]

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Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 25 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2248445350434852 4.4233e-08  
a 2.673496707595537 1.171e-08 au
q 2.07237558343593 1.2172e-07 au
i 4.886317877957711 3.8714e-06 deg
node 75.56619209889605 5.4223e-05 deg
peri 316.6367142102745 5.4827e-05 deg
M 241.6390834573522 9.3946e-06 deg
tp 2459725.456993788612
(2022-May-25.95699379)
4.3919e-05 TDB
period 1596.68008058898
4.37
1.049e-05
2.872e-08
d
yr
n .2254678343999907 1.4813e-09 deg/d
Q 3.274617831755144 1.4342e-08 au
  Orbit Determination Parameters
   # obs. used (total)      1073  
   data-arc span      15183 days (41.57 yr)  
   first obs. used      1978-11-29  
   last obs. used      2020-06-24  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .52532  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Nov-13 01:59:01  

Additional Information
 Earth MOID = 1.08075 au 
 Jupiter MOID = 2.16974 au 
 T_jup = 3.338 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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

[ show close-approach data ]
Alternate Designations
 1991 UL4 = 1978 WW1 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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