+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   18373 (1991 RQ16) Classification: Main-belt Asteroid          SPK-ID: 2018373 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2456400.5 (2013-Apr-18.0) TDB Reference: MPO234934 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 0.1554753 n/a   a 2.6812236 n/a AU q 2.2643596 n/a AU i 4.09482 n/a deg node 72.09687 n/a deg peri 258.97012 n/a deg M 349.77803 n/a deg tp 2456446.0333996 (2013-Jun-02.53339960) n/a JED period 1603.6071182 4.39 n/a n/a d yr n 0.22449389 n/a deg/d Q 3.0980876 n/a AU   Orbit Determination Parameters    # obs. used (total)      547      first obs. used      1991-??-??      last obs. used      2012-06-16      # oppositions      12      planetary ephem.      DE403      condition code      0      fit RMS      0.57      data source      MPC:mpn      producer      MPCLINUX   Additional Information  T_jup = 3.355  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 14.9 mag n/a PDS3 (MPO 5174)   18373 (1991 RQ16)          Discovered 1991-Sep-15 by Holt, H. E. at Palomar (675) Reference: 20001111/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1991 RQ16 = 1996 XN13  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] 2013-Jun-19 23:48 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin