+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   4648 Tirion (1931 UE) Classification: Main-belt Asteroid          SPK-ID: 2004648 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2456400.5 (2013-Apr-18.0) TDB Reference: MPO250251 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 0.1857813 n/a   a 2.3942491 n/a AU q 1.9494424 n/a AU i 9.79248 n/a deg node 319.72820 n/a deg peri 123.16827 n/a deg M 319.57016 n/a deg tp 2456552.4679305 (2013-Sep-16.96793050) n/a JED period 1353.1702072 3.70 n/a n/a d yr n 0.26604192 n/a deg/d Q 2.8390558 n/a AU   Orbit Determination Parameters    # obs. used (total)      626      first obs. used      1931-??-??      last obs. used      2012-12-07      # oppositions      17      planetary ephem.      DE403      condition code      0      fit RMS      0.51      data source      MPC:mpn      producer      MPCLINUX   Additional Information  T_jup = 3.487  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 13.20 mag n/a IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 4 diameter diameter 12.29 km 0.8 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 4 geometric albedo albedo 0.0614   0.009 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 4 4648 Tirion (1931 UE)          Discovered 1931-Oct-18 by Reinmuth, K. at Heidelberg (024) Reference: DISCOVERY.DB Last Updated: 2003-08-29 Alternate Designations  1931 UE = 1977 CA1  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] 2013-May-18 13:42 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin