+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   12620 Simaqian (6335 P-L) Classification: Main-belt Asteroid          SPK-ID: 2012620 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 23 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .144631116578833 2.8558e-08   a 3.095552426337713 1.7093e-08 au q 2.647839222488174 8.7943e-08 au i .9185386567357877 4.4463e-06 deg node 180.0190089641718 0.00023838 deg peri 59.27892983573945 0.00023899 deg M 79.94497524121986 1.7289e-05 deg tp 2458558.731908579455 (2019-Mar-16.23190858) 9.4765e-05 TDB period 1989.324687780959 5.45 1.6477e-05 4.511e-08 d yr n .1809659339228182 1.4989e-09 deg/d Q 3.543265630187252 1.9565e-08 au   Orbit Determination Parameters    # obs. used (total)      1536      data-arc span      21861 days (59.85 yr)      first obs. used      1960-09-24      last obs. used      2020-08-01      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .54686      source      ORB      producer      Otto Matic      solution date      2020-Aug-25 00:35:23   Additional Information  Earth MOID = 1.63574 au   Jupiter MOID = 1.46487 au   T_jup = 3.207  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 13.8   n/a MPO473937   12620 Simaqian           Discovered 1960 Sept. 24 by C. J. van Houten and I. van Houten-Groeneveld on Palomar Schmidt plates taken by T. Gehrels. Sima Qian (c. 145 B.C.-c. 85 B.C.) was a Chinese historian, counselor and court astrologer of the Han emperor Wu Di. He wrote a treatise on the Chinese calendar. His Shiji ("Records of the Grand Historian") contains the earliest systematical description of the Chinese constellations. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20080122/MPCPages.arc Last Updated: 2008-03-05 [ show close-approach data ] Alternate Designations  6335 P-L = 1992 OD8 = 1996 DD7  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Oct-21 20:24 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin