+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   46P/Wirtanen Classification: Jupiter-family Comet [NEO]          SPK-ID: 1000109 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] alternate orbits: [epoch=2018-Dec-13.0] K181/21 (default) [epoch=2018-Dec-03.0] K182/10 [epoch=2007-Jul-21.0] K133/1 [epoch=2006-Sep-15.0] K085/1 [epoch=1999-May-22.0] J973/32 [epoch=1997-Mar-13.0] SAO/1997 [epoch=1991-Sep-21.0] SAO/1991 [epoch=1986-Mar-31.0] SAO/1986 [epoch=1974-Jul-12.0] SAO/1974 [epoch=1967-Dec-16.0] SAO/1967 [epoch=1961-Apr-11.0] SAO/1961 [epoch=1954-Aug-06.0] SAO/1954 [epoch=1947-Dec-01.0] SAO/1947 Orbital Elements at Epoch 2458465.5 (2018-Dec-13.0) TDB Reference: JPL K181/21 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .6587597216166052 2.1734e-07   a 3.092705740644532 1.9746e-06 au q 1.055355767895463 5.2694e-09 au i 11.74759274314818 3.1571e-06 deg node 82.15763882934478 3.4456e-06 deg peri 356.3410943543136 6.7842e-06 deg M .01246725115992296 7.8481e-07 deg tp 2458465.431202202407 (2018-Dec-12.93120220) 4.3507e-06 TDB period 1986.581229156295 5.44 0.0019025 5.209e-06 d yr n .1812158469618142 1.7355e-07 deg/d Q 5.1300557133936 3.2754e-06 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 4.018869937057035E-9 4.8E-11 A2 [EST] -1.352227436938086E-9 4.935E-11 A3 [EST] 8.151537858252997E-10 3.163E-11   Orbit Determination Parameters    # obs. used (total)      4135      # delay obs. used      4      # Doppler obs. used      1      data-arc span      414 days (1.13 yr)      first obs. used      2018-05-08      last obs. used      2019-06-26      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      2      norm. resid. RMS      .46437      source      ORB      producer      Javier Roa      solution date      2020-Aug-06 09:05:10   Additional Information  Earth MOID = .0713354 au   Jupiter MOID = .169237 au   T_jup = 2.818  [ 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 comet total magnitude M1 16.5   0.9 K181/21 2 parameter fit from 2327 observations, autocmod 2.8 comet total magnitude slope K1 4.5   n/a K181/21 autocmod 2.8 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   1975.4       1974 XI   1974i   1964.6       1967 XIV   1967k   1959.1       1961 IV   1960m   1953.7   46P/1954 R2   1954 XI   1954j   1948.2   46P/1948 A1   1947 XIII   1948b  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Feb-25 17:14 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin