+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   C/2015 X4 (Elenin) Classification: Jupiter-family Comet          SPK-ID: 1003424 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters ] [ show orbit diagram ] Orbital Elements at Epoch 2457415.5 (2016-Jan-28.0) TDB Reference: JPL 21 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .8128069022727644 6.652e-06   a 18.13466534731507 0.00065231 au q 3.394684182610662 4.0814e-06 au i 29.50490070566778 4.1461e-05 deg node 262.6358029046453 2.3835e-05 deg peri 176.3289764086126 0.00014965 deg M 1.091619495690537 6.3643e-05 deg tp 2457329.967428745413 (2015-Nov-03.46742875) 0.00067518 TDB period 28207.37974469124 77.23 1.5219 0.004167 d yr n .01276261755818541 6.8861e-07 deg/d Q 32.87464651201947 0.0011825 au   Orbit Determination Parameters    # obs. used (total)      599      data-arc span      823 days (2.25 yr)      first obs. used      2014-12-22      last obs. used      2017-03-24      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      3      norm. resid. RMS      .40517      source      ORB      producer      Otto Matic      solution date      2021-Apr-15 23:33:20   Additional Information  Earth MOID = 2.41104 au   Jupiter MOID = 1.7007 au   T_jup = 2.180  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes comet total magnitude M1 13.1   0.9 21 2 parameter fit from 323 observations, autocmod 2.9c comet total magnitude slope K1 4.5   n/a 21 autocmod 2.9c Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   2015.8   C/2015 X4        [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters ] 2021-May-07 08:42 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin