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JPL Small-Body Database Browser
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20987 (1981 EU38)
Classification: Main-belt Asteroid          SPK-ID: 2020987
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 25 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1343527961032525 3.4873e-08  
a 2.251027615917972 7.51e-09 au
q 1.948595761613754 7.7642e-08 au
i 3.174642502442211 4.8503e-06 deg
node 204.0224048737861 6.2506e-05 deg
peri 43.78841515385144 6.488e-05 deg
M 165.8568393072983 1.7209e-05 deg
tp 2458432.170046989361
(2018-Nov-09.67004699)
5.8508e-05 TDB
period 1233.586651827791
3.38
6.1733e-06
1.69e-08
d
yr
n .2918319515427572 1.4604e-09 deg/d
Q 2.55345947022219 8.519e-09 au
  Orbit Determination Parameters
   # obs. used (total)      1414  
   data-arc span      14167 days (38.79 yr)  
   first obs. used      1981-02-12  
   last obs. used      2019-11-27  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .51378  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-Dec-14 00:48:03  

Additional Information
 Earth MOID = .936458 au 
 Jupiter MOID = 2.46525 au 
 T_jup = 3.613 
[ hide covariance matrix ]
Orbital Elements at Epoch 2456879.5 (2014-Aug-10.0) TDB
Reference: JPL 25 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1341526668415273 3.4897e-08  
q 1.949563495169848 7.7639e-08 au
tp 2457198.589376227355
(2015-Jun-25.08937623)
5.8176e-05 TDB
node 204.0504737755132 6.2506e-05 deg
peri 43.73941044530014 6.4889e-05 deg
i 3.173938019879907 4.8506e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      1414  
   data-arc span      14167 days (38.79 yr)  
   first obs. used      1981-02-12  
   last obs. used      2019-11-27  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .51378  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-Dec-14 00:48:03  

Additional Information
 Jupiter MOID = 2.46525 au 
 T_jup = 3.613 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.217777178214896E-15 -2.700015983295838E-15 -6.804158899666443E-13 7.445597855627718E-15 -2.267754290824796E-13 -2.166765852363458E-16
q -2.700015983295838E-15 6.027864033950655E-15 1.543247732275913E-12 -1.680755173367347E-14 5.099536646435849E-13 4.483746265583321E-16
tp -6.804158899666443E-13 1.543247732275913E-12 3.384489668392776E-9 -1.250025218552165E-11 1.021164798971418E-9 3.530011445434924E-13
node 7.445597855627718E-15 -1.680755173367347E-14 -1.250025218552165E-11 3.907028696774337E-9 -3.904139465513453E-9 -6.027851774754701E-11
peri -2.267754290824796E-13 5.099536646435849E-13 1.021164798971418E-9 -3.904139465513453E-9 4.210530648971415E-9 6.030073345962378E-11
i -2.166765852363458E-16 4.483746265583321E-16 3.530011445434924E-13 -6.027851774754701E-11 6.030073345962378E-11 2.352877991797734E-11

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 MPO395204  
diameter diameter 2.791 km 0.560 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2016AJ....152...63N)  
geometric albedo albedo 0.299   0.154 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2016AJ....152...63N)  

20987 (1981 EU38)          Discovered 1981-Mar-01 by Bus, S. J. at Siding Spring
Reference: 20010208/Numbers.arcLast Updated: 2004-04-19
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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