+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   12P/Pons-Brooks Classification: Halley-type Comet* [NEO]          SPK-ID: 1000068 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] alternate orbits: [epoch=1954-09-15.0] 15 (default) [epoch=1884-01-25.0] SAO/1884 [epoch=1812-08-30.0] SAO/1812 Orbital Elements at Epoch 2435000.5 (1954-Sep-15.0) TDB Reference: JPL 15 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 0.9548123941619716115170 3.0452e-08   a 17.121223241407509618738 1.546e-05 AU q 0.7736670872976132429243 7.9e-07 AU i 74.176894232522556649200 4.0465e-05 deg node 255.8911443583019 8.6118e-05 deg peri 199.028468565403 0.00015453 deg M 1.601583044410965 6.1764e-06 deg tp 2434885.380850198988 (1954-May-22.88085020) 0.00033916 JED period 25876.20671496702 70.85 0.035049 9.596e-05 d yr n .01391239465527121 1.8844e-08 deg/d Q 33.4687793955174 3.0222e-05 AU Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] -1.021678908475834E-9 2.949E-10 A2 [EST] -2.705135237076094E-10 8.372E-14   Orbit Determination Parameters    # obs. used (total)      278      data-arc span      51861 days (141.99 yr)      first obs. used      1812-08-26      last obs. used      1954-08-23      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      fit RMS      1.1877      data source      ORB      producer      M.S.W. Keesey      solution date      2001-Nov-05 15:37:25   Additional Information  Earth MOID = .1873 AU   T_jup = 0.598  [ 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 5. mag n/a MPC data tape   comet total magnitude slope K1 15.0   n/a MPC data tape   comet nuclear magnitude M2 11. mag n/a MPC data tape   comet nuclear magnitude slope K2 10.0   n/a MPC data tape   12P/Pons-Brooks          Discovered 1812-Jul-21 by Pons, Jean Louis at Marseilles, France Reference: comet.dis Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   1954.4   12P/1953 M1   1954 VII   1953c   1883.5   12P/1883 R1   1884 I   1883b   1812.7   12P/1812 O1   1812     [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2013-May-25 06:19 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin