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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 2458600.5 (2019-Apr-27.0) TDB
Reference: JPL 19 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .0481621951369952 4.6021e-08  
a 5.320209872776798 1.0263e-07 au
q 5.063976886714354 2.926e-07 au
i 14.64088479617559 5.7386e-06 deg
node 188.7893163748141 1.8094e-05 deg
peri 114.5596118387386 6.7421e-05 deg
M 260.8799647299666 6.8491e-05 deg
tp 2459834.600479820726
(2022-Sep-12.10047982)		 0.00086991 TDB
period 4482.203537610905
12.27		 0.00012969
3.551e-07		 d
yr
n .08031763773759512 2.324e-09 deg/d
Q 5.576442858839243 1.0757e-07 au
   Orbit Determination Parameters
   # obs. used (total)      1413  
   data-arc span      23516 days (64.38 yr)  
   first obs. used      1954-12-22  
   last obs. used      2019-05-11  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .4941  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-May-29 19:28:05  

Additional Information
 Earth MOID = 4.08031 au 
 Jupiter MOID = .0645291 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 10.7   n/a MPO435714  
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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