+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   46P/Wirtanen Classification: Jupiter-family Comet [NEO]          SPK-ID: 1000109 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] alternate orbits: [epoch=2008-08-01.0] K073/13 (default) [epoch=1999-05-22.0] J973/32 [epoch=1997-03-13.0] SAO/1997 [epoch=1991-09-21.0] SAO/1991 [epoch=1986-03-31.0] SAO/1986 [epoch=1974-07-12.0] SAO/1974 [epoch=1967-12-16.0] SAO/1967 [epoch=1961-04-11.0] SAO/1961 [epoch=1954-08-06.0] SAO/1954 [epoch=1947-12-01.0] SAO/1947 Orbital Elements at Epoch 2454679.5 (2008-Aug-01.0) TDB Reference: JPL K073/13 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 0.6581045255110213876292 6.2724e-08   a 3.0927929625788861400792 1.413e-07 AU q 1.0574119174370819607133 1.855e-07 AU i 11.739497488131389602017 1.1029e-05 deg node 82.17175978824024 4.9228e-05 deg peri 356.340556123535 5.4052e-05 deg M 32.71045478768135 6.0105e-06 deg tp 2454498.986876455914 (2008-Feb-02.48687646) 2.7524e-05 JED period 1986.665269488824 5.44 0.00013614 3.727e-07 d yr n .1812081811309005 1.2418e-08 deg/d Q 5.128174007720689 2.3428e-07 AU Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 3.702962232871687E-9 5.808E-11 A2 [EST] -1.307234620904696E-9 1.165E-11 A3 [EST] 8.00875738049421E-10 3.063E-11 DT [EST] -4.174593125582905 .6095   Orbit Determination Parameters    # obs. used (total)      1815      data-arc span      4746 days (12.99 yr)      first obs. used      1995-06-26      last obs. used      2008-06-23      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      condition code      0      fit RMS      .80053      data source      ORB      producer      Nick Mastrodemos      solution date      2008-Aug-19 12:53:49   Additional Information  Earth MOID = .071863 AU   T_jup = 2.819  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes comet total magnitude M1 12.3 mag 1. K073/13 2 parameter fit from 308 observations, autocmod 2.4a comet total magnitude slope K1 15.   n/a K073/13 autocmod 2.4a comet nuclear magnitude M2 15.9 mag 01. K073/13 from 1092 observations, autocmod 2.4a comet nuclear magnitude slope K2 5.   n/a K073/13 autocmod 2.4a comet nuclear phase coefficient PC 0.03   n/a K073/13 autocmod 2.4a diameter diameter 1.2 km n/a Lamy,P.L.,Toth,I.,Fernandez,Y.R.,Weaver,H.A. (2004) Comets II, pp. 223-264   46P/Wirtanen          Discovered 1948-Jan-15 by Wirtanen, Carl A. at Lick Observatory, California discovered on plate/photo taken on discovery date Reference: comet.dis Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   1991.8       1991 XVI   1991s   1986.3       1986 VI   1985q   1975.5       1974 XI   1974i   1964.6       1967 XIV   1967k   1959.1       1961 IV   1960m   1953.7   46P/1954 R2   1954 XI   1954j   1948.3   46P/1948 A1   1947 XIII   1948b  [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2013-Jun-19 14:13 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin