+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   51P/Harrington Classification: Jupiter-family Comet          SPK-ID: 1000038 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] alternate orbits: [epoch=2015-Oct-05.0] K153/2 (default) [epoch=2009-Jan-10.0] K084/6 [epoch=1987-Oct-12.0] SAO/1987 [epoch=1980-Dec-27.0] SAO/1980 [epoch=1960-Jul-05.0] SAO/1960 [epoch=1953-Sep-20.0] SAO/1953 Orbital Elements at Epoch 2457300.5 (2015-Oct-05.0) TDB Reference: JPL K153/2 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .542437041421476 6.3875e-07   a 3.71446643000283 4.664e-06 au q 1.699602249252703 1.8812e-06 au i 5.424389279818731 2.2061e-05 deg node 83.70082476433753 0.0011047 deg peri 269.2756022819647 0.0013286 deg M 7.34011923544291 8.6373e-05 deg tp 2457247.185701714257 (2015-Aug-12.68570171) 0.00053386 TDB period 2614.827738790723 7.16 0.0049249 1.348e-05 d yr n .1376763733455302 2.5931e-07 deg/d Q 5.729330610752958 7.194e-06 au Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 3.867415007133801E-8 6.86E-10 A2 [EST] 3.996867447334527E-9 9.509E-12 A3 [EST] -7.129200060302572E-9 8.432E-10   Orbit Determination Parameters    # obs. used (total)      653      data-arc span      5085 days (13.92 yr)      first obs. used      2001-09-23      last obs. used      2015-08-26      planetary ephem.      DE431      SB-pert. ephem.      SB431-BIG16      condition code      2      norm. resid. RMS      .86271      source      ORB      producer      Alan B. Chamberlin      solution date      2015-Oct-07 10:04:30   Additional Information  Earth MOID = .704944 au   T_jup = 2.814  [ 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 11.8   2. K153/2 2 parameter fit from 143 observations, autocmod 2.6 comet total magnitude slope K1 14.   n/a K153/2 autocmod 2.6 comet nuclear magnitude M2 15.1   0.9 K153/2 from 440 observations, autocmod 2.6 comet nuclear magnitude slope K2 5.   n/a K153/2 autocmod 2.6 comet nuclear phase coefficient PC 0.03   n/a K153/2 autocmod 2.6 diameter diameter 4.8 km n/a Scotti,J (1994) BAAS 26:1375   51P/Harrington          Discovered 1953-Aug-14 by Harrington, Robert G. at Palomar Mountain 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   1994.1       1994 XXII   1994g   1987.0       1987 XXVIII   1987n   1979.8       1980 XIV   1980m   1958.3   51P/1960 P1   1960 VII   1960g   1951.2   51P/1953 P1   1953 VI   1953e  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jun-25 02:13 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin