+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   18282 Ilos (4369 T-3) Classification: Jupiter Trojan          SPK-ID: 2018282 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 18 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .07556260513711928 5.3015e-08   a 5.232030272825171 1.0496e-07 au q 4.836684435254228 3.0582e-07 au i 8.703029919171644 5.2593e-06 deg node 164.4022792969321 3.3618e-05 deg peri 212.493365381371 5.1938e-05 deg M 239.2028241862703 4.4316e-05 deg tp 2460667.256694745427 (2024-Dec-22.75669475) 0.00056593 TDB period 4371.231417881691 11.97 0.00013153 3.601e-07 d yr n .08235665550154213 2.4781e-09 deg/d Q 5.627376110396114 1.1289e-07 au   Orbit Determination Parameters    # obs. used (total)      664      data-arc span      15616 days (42.75 yr)      first obs. used      1977-10-16      last obs. used      2020-07-18      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .49982      source      ORB      producer      Otto Matic      solution date      2020-Nov-13 02:15:55   Additional Information  Earth MOID = 3.84005 au   Jupiter MOID = .100796 au   T_jup = 2.971  [ 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 12.46   n/a E2021B10   diameter diameter 15.422 km 1.038 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2011ApJ...742...40G)   geometric albedo albedo 0.089   0.020 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2011ApJ...742...40G)   18282 Ilos           Discovered 1977 Oct. 16 by C. J. van Houten and I. van Houten-Groeneveld on Palomar Schmidt plates taken by T. Gehrels. Ilos was the oldest son of Tros, and he built the citadel Ilion, also named Ilios. Ilos was the father of Laomedon and the grandfather of Priam. 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.arc Last Updated: 2009-05-11 Alternate Designations  4369 T-3 = 1988 RF12  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Mar-03 03:14 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin