+ 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 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 29 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1444911440322285 2.7216e-08   a 3.094421051848771 1.5054e-08 au q 2.64730461394973 8.1272e-08 au i .918734955903334 4.3643e-06 deg node 180.0174005841491 0.00019387 deg peri 59.09240748669308 0.00019455 deg M 151.8616888376314 1.7204e-05 deg tp 2458557.787217666922 (2019-Mar-15.28721767) 9.2932e-05 TDB period 1988.23418829969 5.44 1.4509e-05 3.972e-08 d yr n .1810651894623475 1.3213e-09 deg/d Q 3.541537489747812 1.7229e-08 au   Orbit Determination Parameters    # obs. used (total)      1797      data-arc span      22050 days (60.37 yr)      first obs. used      1960-09-24      last obs. used      2021-02-06      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .52918      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 16:49:59   Additional Information  Earth MOID = 1.63558 au   Jupiter MOID = 1.46385 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 13.78   n/a E2021B10   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 ] 2021-Jul-25 13:58 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin