+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   16538 (1991 PO12) Classification: Main-belt Asteroid          SPK-ID: 2016538 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2456400.5 (2013-Apr-18.0) TDB Reference: MPO256985 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 0.1713399 n/a   a 2.2687506 n/a AU q 1.8800231 n/a AU i 5.12358 n/a deg node 145.69971 n/a deg peri 273.85861 n/a deg M 46.67787 n/a deg tp 2456238.6595460 (2012-Nov-07.15954600) n/a JED period 1248.1838492 3.42 n/a n/a d yr n 0.28841905 n/a deg/d Q 2.6574781 n/a AU   Orbit Determination Parameters    # obs. used (total)      934      first obs. used      1987-??-??      last obs. used      2013-03-03      # oppositions      13      planetary ephem.      DE403      condition code      0      fit RMS      0.53      data source      MPC:mpn      producer      MPCLINUX   Additional Information  T_jup = 3.589  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 13.9 mag n/a PDS3 (MPO 2862)   16538 (1991 PO12)          Discovered 1991-Aug-05 by Holt, H. E. at Palomar (675) Reference: 20000913/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1991 PO12 = 1998 QA102  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] 2013-May-25 17:05 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin