+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   23P/Brorsen-Metcalf Classification: Halley-type Comet* [NEO]          SPK-ID: 1000009 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] alternate orbits: [epoch=1989-10-01.0] 13 (default) [epoch=1919-10-09.0] SAO/1919 [epoch=1847-09-16.0] SAO/1847 Orbital Elements at Epoch 2447800.5 (1989-Oct-01.0) TDB Reference: JPL 13 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e 0.9719522579248509597249 6.9621e-07   a 17.069206834622299595594 0.00041942 AU q 0.4787527107248574775866 8.3143e-07 AU i 19.333940469818628571374 5.3648e-05 deg node 311.5854622141069 0.00012597 deg peri 129.6106836788667 0.00021024 deg M .2664191525503107 1.0108e-05 deg tp 2447781.437433134682 (1989-Sep-11.93743313) 2.7505e-05 JED period 25758.37362225135 70.52 0.94939 0.002599 d yr n .01397603766757286 5.1512e-07 deg/d Q 33.65966095851974 0.00082707 AU Additional Model Parameters  Parameter Value Uncertainty (1-sigma)  A1 [EST] 2.24654685575494E-9 2.147E-10 A2 [EST] -5.326929396349485E-10 6.488E-14   Orbit Determination Parameters    # obs. used (total)      223      data-arc span      51904 days (142.11 yr)      first obs. used      1847-08-01      last obs. used      1989-09-09      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      condition code      0      fit RMS      1.2347      data source      ORB      producer      M.S.W. Keesey      solution date      2002-Mar-01 13:24:57   Additional Information  Earth MOID = .193872 AU   T_jup = 1.109  [ 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 7.8 mag n/a ICQ 1991 Handbook   comet total magnitude slope K1 8.0   n/a ICQ 1991 Handbook   comet nuclear magnitude M2 14. mag n/a ICQ 1991 Handbook   comet nuclear magnitude slope K2 5.0   n/a ICQ 1991 Handbook   comet nuclear phase coefficient PC 0.03   n/a ICQ 1991 Handbook   23P/Brorsen-Metcalf          Discovered 1847-Jul-20 by Brorsen, T. at Altona Observatory, Germany Reference: comet.dis Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  Perihelion  Year (est.)  New-Style  Desig Roman  Numeral  Year/  Letter   1989.7   23P/1989 N1   1989 X   1989o   1919.2   23P/1919 Q1   1919 III   1919b   1848.6   23P/1847 O1   1847 V    [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2013-May-24 09:52 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin