+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   6490 (1991 NR2) Classification: Mars-crossing Asteroid          SPK-ID: 2006490 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2456400.5 (2013-Apr-18.0) TDB Reference: MPO236430 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 0.4088650 n/a   a 2.6569560 n/a AU q 1.5706197 n/a AU i 17.29705 n/a deg node 286.86525 n/a deg peri 28.22004 n/a deg M 3.57426 n/a deg tp 2456384.7942524 (2013-Apr-02.29425240) n/a JED period 1581.8852346 4.33 n/a n/a d yr n 0.22757656 n/a deg/d Q 3.7432923 n/a AU   Orbit Determination Parameters    # obs. used (total)      340      first obs. used      1982-??-??      last obs. used      2012-04-27      # oppositions      15      planetary ephem.      DE403      condition code      0      fit RMS      0.51      data source      MPC:mpn      producer      MPCLINUX   Additional Information  T_jup = 3.204  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 14.1 mag n/a PDS3 (MPC 25419)   rotation period rot_per 4.468 h n/a Asteroid Lightcurve DataBase (Rev. 2013-May-01) Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Published Reference List: [Behrend, R. (2004) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Warner, B.D. (2005) Minor Planet Bul. 32, 4-7.] 6490 (1991 NR2)          Discovered 1991-Jul-12 by Holt, H. E. at Palomar (675) Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ] 2013-May-24 13:36 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin