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1961 Dufour (1973 WA)
Classification: Main-belt Asteroid          SPK-ID: 2001961
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 46 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1245994033630563 3.1812e-08  
a 3.19349514471887 1.4175e-08 au
q 2.795587555044082 1.0457e-07 au
i 6.647918111350678 4.3435e-06 deg
node 29.57712569388118 2.934e-05 deg
peri 56.67314223492998 3.3945e-05 deg
M .1990113851508618 1.6759e-05 deg
tp 2458999.347679630666
(2020-May-29.84767963)
9.7036e-05 TDB
period 2084.480406212979
5.71
1.3878e-05
3.8e-08
d
yr
n .1727049095433989 1.1499e-09 deg/d
Q 3.591402734393658 1.5941e-08 au
  Orbit Determination Parameters
   # obs. used (total)      3828  
   data-arc span      20925 days (57.29 yr)  
   first obs. used      1962-12-31  
   last obs. used      2020-04-15  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .35471  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-May-20 01:32:57  

Additional Information
 Earth MOID = 1.81868 au 
 Jupiter MOID = 1.67631 au 
 T_jup = 3.174 
[ hide covariance matrix ]
Orbital Elements at Epoch 2456191.5 (2012-Sep-21.0) TDB
Reference: JPL 46 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1210834003855233 3.1993e-08  
q 2.807507299536173 1.0474e-07 au
tp 2456921.344245096594
(2014-Sep-20.84424510)
9.8923e-05 TDB
node 29.71745997215286 2.9399e-05 deg
peri 57.65914219125391 3.4206e-05 deg
i 6.640914738642437 4.3368e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      3828  
   data-arc span      20925 days (57.29 yr)  
   first obs. used      1962-12-31  
   last obs. used      2020-04-15  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .35471  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-May-20 01:32:57  

Additional Information
 Jupiter MOID = 1.67631 au 
 T_jup = 3.174 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.023560935360759E-15 -3.327170801976698E-15 -6.135514047972945E-13 2.81215208613997E-15 -9.960167705050276E-14 -3.989204313816745E-16
q -3.327170801976698E-15 1.096999089826433E-14 1.877140629521491E-12 -9.560897223969719E-15 2.926869430984907E-13 1.621326312846874E-15
tp -6.135514047972945E-13 1.877140629521491E-12 9.785761327252151E-9 -8.188668717132786E-12 1.740873417012192E-9 1.687034351004089E-12
node 2.81215208613997E-15 -9.560897223969719E-15 -8.188668717132786E-12 8.64311246727247E-10 -8.596489855136617E-10 -1.002888963042512E-11
peri -9.960167705050276E-14 2.926869430984907E-13 1.740873417012192E-9 -8.596489855136617E-10 1.170074356013345E-9 1.020232511509548E-11
i -3.989204313816745E-16 1.621326312846874E-15 1.687034351004089E-12 -1.002888963042512E-11 1.020232511509548E-11 1.88075817046427E-11

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 10.8   n/a MPO502172  
diameter diameter 50.31 km 1.6 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 20
rotation period rot_per 15.79 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List:
[Behrend, R. (2010) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.]
geometric albedo albedo 0.0402   0.003 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 20

1961 Dufour (1973 WA)          Discovered 1973-Nov-19 by Wild, P. at Zimmerwald
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 1973 WA = 1927 UM = 1952 BQ1 = 1962 YG = 1969 AH = 1973 SY3 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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