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(2009 HD21)
Classification: Apollo [NEO, PHA]          SPK-ID: 3457843
[ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ]

[ hide orbit diagram ]

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.


Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 45 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .6881621506423056 2.6964e-08  
a 2.771934973931498 7.3977e-08 au
q .8643942408301752 8.3776e-08 au
i 18.64197251964715 2.4374e-05 deg
node 179.2359074710641 2.2179e-05 deg
peri 134.2529869130026 2.3616e-05 deg
M 164.3062660817182 3.6125e-05 deg
tp 2458431.148846154196
(2018-Nov-08.64884615)		 0.00013837 TDB
period 1685.671654462279
4.62		 6.7481e-05
1.848e-07		 d
yr
n .2135647230271771 8.5494e-09 deg/d
Q 4.679475707032822 1.2489e-07 au
   Orbit Determination Parameters
   # obs. used (total)      146  
   data-arc span      3281 days (8.98 yr)  
   first obs. used      2009-03-24  
   last obs. used      2018-03-18  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .46975  
   source      ORB  
   producer      Otto Matic  
   solution date      2018-Mar-19 06:25:31  

Additional Information
 Earth MOID = .0126196 au 
 Jupiter MOID = 1.30922 au 
 T_jup = 2.881 
[ show covariance matrix ]

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

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 18.2   n/a MPO166339  

[ show close-approach data ]
[ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ]
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