+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   11876 Doncarpenter (1990 EM1) Classification: Main-belt Asteroid          SPK-ID: 2011876 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 36 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .15574808693336 2.8338e-08   a 2.430256829763423 6.5966e-09 au q 2.051748977771038 7.0499e-08 au i 5.406038582459714 3.4777e-06 deg node 234.0936122736215 3.3096e-05 deg peri 92.57475943572429 3.5007e-05 deg M 305.1664362229795 1.2376e-05 deg tp 2459607.275756783294 (2022-Jan-27.77575678) 4.7884e-05 TDB period 1383.810703067693 3.79 5.6343e-06 1.543e-08 d yr n .2601511891777799 1.0592e-09 deg/d Q 2.808764681755809 7.624e-09 au   Orbit Determination Parameters    # obs. used (total)      2158      data-arc span      11445 days (31.33 yr)      first obs. used      1990-02-24      last obs. used      2021-06-26      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .46414      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 02:49:20   Additional Information  Earth MOID = 1.04819 au   Jupiter MOID = 2.52934 au   T_jup = 3.485  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 14.22   n/a MPO614063   11876 Doncarpenter           Discovered 1990 Mar. 2 by E. W. Elst at the European Southern Observatory. For the past 42 years, Don Carpenter (b. 1938) has been associated with the Stanford research group devoted to passive and active whistler-mode probing of the earth's ionosphere and magnetosphere. In 1966 he discovered the plasmapause in the electron-density distribution of the magnetosphere. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20010509/MPCPages.arc Last Updated: 2009-05-11 Alternate Designations  1990 EM1 = 1995 QR2  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jul-29 23:27 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin