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4021 Dancey (1981 QD2)
Classification: Main-belt Asteroid          SPK-ID: 2004021
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

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For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.


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Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 31 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1694767286967866 3.9359e-08  
a 2.282695898945585 6.0876e-09 au
q 1.895832065382717 9.0422e-08 au
i 3.542124515785396 3.8991e-06 deg
node 49.5647039251129 6.6177e-05 deg
peri 327.0437544140322 6.7216e-05 deg
M 59.97421424994204 1.0686e-05 deg
tp 2458790.638592750321
(2019-Nov-03.13859275)
3.7473e-05 TDB
period 1259.709819540609
3.45
5.0392e-06
1.38e-08
d
yr
n .2857801014294583 1.1432e-09 deg/d
Q 2.669559732508453 7.1193e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2207  
   data-arc span      23032 days (63.06 yr)  
   first obs. used      1957-10-01  
   last obs. used      2020-10-22  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .45615  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Nov-13 03:55:07  

Additional Information
 Earth MOID = .898656 au 
 Jupiter MOID = 2.79215 au 
 T_jup = 3.583 
[ 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 13.5   n/a MPO344332  
diameter diameter 4.543 km 0.033 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.374   0.069 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

4021 Dancey (1981 QD2)          Discovered 1981-Aug-30 by Bowell, E. at Flagstaff (AM)
Discovered at the Anderson Mesa station, which is operated by the Lowell Observatory.
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 1981 QD2 = 1950 SV = 1957 TE = 1957 UF = 1986 AV 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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