+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   1691 Oort (1956 RB) Classification: Main-belt Asteroid          SPK-ID: 2001691 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2456400.5 (2013-Apr-18.0) TDB Reference: JPL 13 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1703992458931409 5.6948e-08   a 3.16558078031878 1.6743e-08 AU q 2.626168202538639 1.8323e-07 AU i 1.078341141843375 5.2342e-06 deg node 174.6696171221579 0.00033565 deg peri 232.9429050096239 0.00033624 deg M 320.0732976410196 1.5678e-05 deg tp 2456628.659979455989 (2013-Dec-02.15997946) 9.0181e-05 JED period 2057.209530245153 5.63 1.6321e-05 4.468e-08 d yr n .1749943283400498 1.3883e-09 deg/d Q 3.70499335809892 1.9596e-08 AU   Orbit Determination Parameters    # obs. used (total)      1246      data-arc span      24494 days (67.06 yr)      first obs. used      1945-10-15      last obs. used      2012-11-06      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      condition code      0      fit RMS      .5959      data source      ORB      producer      Otto Matic      solution date      2013-Mar-29 14:29:46   Additional Information  Earth MOID = 1.63552 AU   T_jup = 3.181  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 10.95 mag n/a PDS3 (MPC 17263)   rotation period rot_per 10.2705 h n/a Asteroid Lightcurve DataBase (Rev. 2013-May-01) Published Reference List: [Behrend, R. (2009) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] B-V BV .682 mag .025 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.1 #obs=1; phase=.75 deg. U-B UB .316 mag .044 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.1 #obs=1; phase=.75 deg. Tholen spectral type spec_T CU   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo 1691 Oort (1956 RB)          Discovered 1956-Sep-09 by Reinmuth, K. and Groeneveld, I. at Heidelberg (024) Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1956 RB = 1945 TD = 1947 DA = 1950 PZ = 1950 RU = 1951 XW = 1955 MW = 1956 SD = 1964 DA = A917 TD  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2013-May-20 01:36 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin