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18317 (1981 EM41)
Classification: Main-belt Asteroid          SPK-ID: 2018317
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 24 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1745851161474155 3.826e-08  
a 3.069277877895641 2.0264e-08 au
q 2.533427643094537 1.216e-07 au
i 5.940166565086224 4.4299e-06 deg
node 340.4057626992769 3.6575e-05 deg
peri 34.86274433863103 3.8419e-05 deg
M 306.0219987870739 1.4683e-05 deg
tp 2459494.987617601392
(2021-Oct-07.48761760)
8.2051e-05 TDB
period 1964.050908782328
5.38
1.945e-05
5.325e-08
d
yr
n .1832946378274852 1.8152e-09 deg/d
Q 3.605128112696744 2.3802e-08 au
  Orbit Determination Parameters
   # obs. used (total)      1259  
   data-arc span      25160 days (68.88 yr)  
   first obs. used      1951-09-04  
   last obs. used      2020-07-23  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .53408  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Apr-13 02:26:27  

Additional Information
 Earth MOID = 1.53555 au 
 Jupiter MOID = 1.89019 au 
 T_jup = 3.200 
[ 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 13.88   n/a E2021B10  
diameter diameter 8.579 km 0.216 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.079   0.025 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

18317 (1981 EM41)          Discovered 1981-Mar-02 by Bus, S. J. at Siding Spring
Reference: 20001111/Numbers.arcLast Updated: 2004-04-19

[ show close-approach data ]
Alternate Designations
 1981 EM41 = 1951 RT = 1994 TF17 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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