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72821 (2001 HW2)
Classification: Main-belt Asteroid          SPK-ID: 2072821
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.


Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 21 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .04661106995755997 4.0924e-08  
a 2.786336674848977 1.6101e-08 au
q 2.656462541172276 1.1444e-07 au
i 3.87468718194901 4.5939e-06 deg
node 215.6077034904483 6.0588e-05 deg
peri 27.86993555166929 7.5736e-05 deg
M 93.36402736556826 4.4979e-05 deg
tp 2458955.918872150239
(2020-Apr-16.41887215)
0.00021231 TDB
period 1698.82566660152
4.65
1.4726e-05
4.032e-08
d
yr
n .2119110907478668 1.8369e-09 deg/d
Q 2.916210808525677 1.6852e-08 au
  Orbit Determination Parameters
   # obs. used (total)      670  
   data-arc span      10187 days (27.89 yr)  
   first obs. used      1993-09-15  
   last obs. used      2021-08-06  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .59115  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Aug-25 01:43:33  

Additional Information
 Earth MOID = 1.64448 au 
 Jupiter MOID = 2.07155 au 
 T_jup = 3.326 
[ hide covariance matrix ]
Orbital Elements at Epoch 2457079.5 (2015-Feb-26.0) TDB
Reference: JPL 21 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .04409311828882283 4.1197e-08  
q 2.661648297660873 1.1434e-07 au
tp 2457254.956607968270
(2015-Aug-20.45660797)
0.00022386 TDB
node 215.7997382463015 6.0581e-05 deg
peri 27.08825171066751 7.7139e-05 deg
i 3.874968911913163 4.5955e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      670  
   data-arc span      10187 days (27.89 yr)  
   first obs. used      1993-09-15  
   last obs. used      2021-08-06  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .59115  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Aug-25 01:43:33  

Additional Information
 Jupiter MOID = 2.07155 au 
 T_jup = 3.326 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.697214847189667E-15 -4.670440594853943E-15 -1.24059412168697E-12 -1.186629884113325E-15 -2.798608450735168E-13 -5.755349424148226E-16
q -4.670440594853943E-15 1.307378360371122E-14 3.158265598243801E-12 2.256022036505778E-15 7.10526283249831E-13 2.021956616112572E-15
tp -1.24059412168697E-12 3.158265598243801E-12 5.01145227223141E-8 9.60036816492267E-12 1.070864885519128E-8 -2.477813181433513E-12
node -1.186629884113325E-15 2.256022036505778E-15 9.60036816492267E-12 3.670085921884633E-9 -3.659117907197282E-9 1.172041235028468E-11
peri -2.798608450735168E-13 7.10526283249831E-13 1.070864885519128E-8 -3.659117907197282E-9 5.950475249300607E-9 -1.219822374371996E-11
i -5.755349424148226E-16 2.021956616112572E-15 -2.477813181433513E-12 1.172041235028468E-11 -1.219822374371996E-11 2.111867809507935E-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 15.35   n/a E2021B10  
diameter diameter 4.691 km 0.149 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.051   0.009 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

72821 (2001 HW2)          Discovered 2001-Apr-17 by LINEAR at Socorro
Reference: 20031109/Numbers.arcLast Updated: 2004-04-19
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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