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1872 Helenos (1971 FG)
Classification: Jupiter Trojan          SPK-ID: 2001872
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 20 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .04876738604851834 4.5065e-08  
a 5.3210209712654 9.9012e-08 au
q 5.061528687387439 2.9037e-07 au
i 14.64024357213536 5.6883e-06 deg
node 188.7879735978422 1.7472e-05 deg
peri 114.4766902461508 6.5888e-05 deg
M 293.1568928045941 6.7192e-05 deg
tp 2459832.924802586242
(2022-Sep-10.42480259)
0.00084742 TDB
period 4483.228585634082
12.27
0.00012513
3.426e-07
d
yr
n .08029927386561836 2.2413e-09 deg/d
Q 5.580513255143361 1.0384e-07 au
  Orbit Determination Parameters
   # obs. used (total)      1511  
   data-arc span      23784 days (65.12 yr)  
   first obs. used      1954-12-22  
   last obs. used      2020-02-03  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .49591  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Feb-22 16:07:03  

Additional Information
 Earth MOID = 4.07874 au 
 Jupiter MOID = .0665004 au 
 T_jup = 2.932 
[ 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 10.8   n/a MPO473789  
diameter diameter 34.046 km 0.603 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)  
geometric albedo albedo 0.067   0.012 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)  

1872 Helenos (1971 FG)          Discovered 1971-Mar-24 by Van Houten, C. J. at Palomar
Discovered by C. J. van Houten and I. van Houten-Groeneveld, Leiden, on plates exposed by T. Gehrels in a survey of faint Trojans with the 122 cm Schmidt camera at Palomar.
Reference: DISCOVERY.DBLast Updated: 2003-08-29
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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