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JPL Small-Body Database Browser
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18281 Tros (4317 T-3)
Classification: Jupiter Trojan          SPK-ID: 2018281
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 16 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1021639036964427 6.0808e-08  
a 5.201517691639577 1.25e-07 au
q 4.670110339115568 3.1568e-07 au
i 9.54291581543508 6.4618e-06 deg
node 171.1831880670726 3.2144e-05 deg
peri 169.7446531885681 4.3746e-05 deg
M 230.4003355131126 3.3993e-05 deg
tp 2460160.393409772020
(2023-Aug-03.89340977)
0.00044586 TDB
period 4333.048466917479
11.86
0.00015619
4.276e-07
d
yr
n .08308238478027068 2.9948e-09 deg/d
Q 5.732925044163586 1.3777e-07 au
  Orbit Determination Parameters
   # obs. used (total)      535  
   data-arc span      15187 days (41.58 yr)  
   first obs. used      1977-10-11  
   last obs. used      2019-05-11  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .5519  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-May-30 02:35:29  

Additional Information
 Earth MOID = 3.66158 au 
 Jupiter MOID = .238486 au 
 T_jup = 2.962 
[ 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 12.4   n/a MPO435869  
diameter diameter 13.976 km 0.738 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2011ApJ...742...40G)  
geometric albedo albedo 0.099   0.024 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2011ApJ...742...40G)  

18281 Tros           Discovered 1977 Oct. 16 by C. J. van Houten and I. van Houten-Groeneveld on Palomar Schmidt plates taken by T. Gehrels.
Tros was a grandson of Dardanos. His country was named Troas after him, and its principal city was Troy.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20010309/MPCPages.arcLast Updated: 2009-05-11

Alternate Designations
 4317 T-3 = 1988 RK12 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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