+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   221P/LINEAR Classification: Jupiter-family Comet          SPK-ID: 1000393 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2455576.5 (2011-Jan-15.0) TDB Reference: JPL 67 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .4874071390337911 2.2719e-07   a 3.474477290256597 1.3716e-07 au q 1.78099225457475 8.273e-07 au i 11.42830130925585 1.9777e-05 deg node 229.9853265169021 4.8978e-05 deg peri 39.56434566500335 9.3342e-05 deg M 109.6463350655327 2.4884e-05 deg tp 2454856.016130395075 (2009-Jan-24.51613040) 0.0001891 TDB period 2365.552782979495 6.48 0.00014008 3.835e-07 d yr n .1521843023712063 9.0118e-09 deg/d Q 5.167962325938444 2.0402e-07 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A2 [EST] -5.338920335334547E-11 5.25E-12   Orbit Determination Parameters    # obs. used (total)      593      data-arc span      6884 days (18.85 yr)      first obs. used      2002-04-14      last obs. used      2021-02-17      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .56314      source      ORB      producer      Otto Matic      solution date      2021-Apr-15 23:27:57   Additional Information  Earth MOID = .783112 au   Jupiter MOID = .312942 au   T_jup = 2.896  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes comet total magnitude M1 13.5   0.6 67 2 parameter fit from 230 observations, autocmod 2.9c comet total magnitude slope K1 15.   n/a 67 autocmod 2.9c comet nuclear magnitude M2 16.4   0.6 67 from 319 observations, autocmod 2.9c comet nuclear magnitude slope K2 5.   n/a 67 autocmod 2.9c comet nuclear phase coefficient PC 0.03   n/a 67 autocmod 2.9c [ show close-approach data ] Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   2009.1   221P/2009 L1         2002.6   221P/2002 JN16        [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ] 2021-Apr-18 11:07 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin