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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 22 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .04876737751174502 4.3007e-08  
a 5.321020937774681 8.8594e-08 au
q 5.061528700954324 2.8877e-07 au
i 14.64024695604115 4.8497e-06 deg
node 188.7879636693374 1.5338e-05 deg
peri 114.4766747895529 5.5381e-05 deg
M 293.1569210298518 5.4421e-05 deg
tp 2459832.924443226488
(2022-Sep-10.42444323)
0.00068335 TDB
period 4483.22854330765
12.27
0.00011197
3.066e-07
d
yr
n .08029927462372866 2.0055e-09 deg/d
Q 5.580513174595038 9.2915e-08 au
  Orbit Determination Parameters
   # obs. used (total)      1756  
   data-arc span      23920 days (65.49 yr)  
   first obs. used      1954-12-22  
   last obs. used      2020-06-18  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .4698  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Jun-23 15:37:47  

Additional Information
 Earth MOID = 4.07874 au 
 Jupiter MOID = .0665005 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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