+ 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 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 27 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1445697787540194 2.7218e-08   a 3.094546408286246 1.5161e-08 au q 2.647168518696258 8.1307e-08 au i .9187415564119241 4.3739e-06 deg node 180.0177309573403 0.00019401 deg peri 59.14577944753987 0.00019469 deg M 116.3008846355983 1.7167e-05 deg tp 2458558.145982880487 (2019-Mar-15.64598288) 9.3251e-05 TDB period 1988.355005962205 5.44 1.4612e-05 4.001e-08 d yr n .1810541874667843 1.3305e-09 deg/d Q 3.541924297876235 1.7352e-08 au   Orbit Determination Parameters    # obs. used (total)      1784      data-arc span      22024 days (60.30 yr)      first obs. used      1960-09-24      last obs. used      2021-01-11      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .52798      source      ORB      producer      Otto Matic      solution date      2021-Feb-24 02:06:56   Additional Information  Earth MOID = 1.63369 au   Jupiter MOID = 1.46478 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-Apr-12 14:05 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin