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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 24 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .04876737650201792 4.2913e-08  
a 5.321020933392627 8.8152e-08 au
q 5.06152870215875 2.8868e-07 au
i 14.64024707204568 4.7561e-06 deg
node 188.7879632170396 1.5204e-05 deg
peri 114.4766716934488 5.489e-05 deg
M 293.156924978106 5.3815e-05 deg
tp 2459832.924393028952
(2022-Sep-10.42439303)
0.00067556 TDB
period 4483.228537769499
12.27
0.00011141
3.05e-07
d
yr
n .0802992747229227 1.9954e-09 deg/d
Q 5.580513164626504 9.2451e-08 au
  Orbit Determination Parameters
   # obs. used (total)      1858  
   data-arc span      24000 days (65.71 yr)  
   first obs. used      1954-12-22  
   last obs. used      2020-09-06  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .46503  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Nov-13 04:14:43  

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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