+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   3221 Changshi (1981 XF2) Classification: Main-belt Asteroid          SPK-ID: 2003221 [ 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 35 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1536280575285813 2.4929e-08   a 2.204018650862031 5.7051e-09 au q 1.865419546773333 5.3667e-08 au i 3.651179848549437 3.2665e-06 deg node 78.60842390088446 5.1604e-05 deg peri 233.2028077718088 5.3298e-05 deg M 18.55776645026341 1.3567e-05 deg tp 2458938.890947624679 (2020-Mar-30.39094762) 4.5027e-05 TDB period 1195.14699759576 3.27 4.6405e-06 1.27e-08 d yr n .3012181771147825 1.1696e-09 deg/d Q 2.54261775495073 6.5816e-09 au   Orbit Determination Parameters    # obs. used (total)      2881      data-arc span      24780 days (67.84 yr)      first obs. used      1953-01-12      last obs. used      2020-11-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .40936      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 02:10:56   Additional Information  Earth MOID = .853855 au   Jupiter MOID = 2.70283 au   T_jup = 3.644  [ 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 13.0   n/a MPO384780   diameter diameter 5.998 km 0.043 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   geometric albedo albedo 0.373   0.050 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   3221 Changshi (1981 XF2)          Discovered 1981-Dec-02 by Purple Mountain Observatory at Nanking Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  1981 XF2 = 1954 KG = 1954 LJ = 1970 GU1 = 1973 DO = 1974 RS1  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-18 20:35 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin